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Breadfan
06-23-2008, 10:48 AM
I wanted to start a thread to try and demystify the LCM - Lighting Control Module. Unfortunately, at the present time, I do not have the required info to demystify, so I'll be looking to the community here to help add input.

The first question is this: What specifically does the LCM do, and what specific systems does it interact with?

For instance, does the LCM simply control the automatic headlights? Does in control all lighting, such as interior lights, dimming, turn signal flashing, hazards, headlights, headlights on w/ wipers, headlights on at dusk, etc.

Does it also control other body-related things such as keyless entry, door keypad, etc. How about any other vehicle functions it controls or interfaces with?

Also, does anyone have a pic of it, either in it's location, or pulled out (or both!). Any pics of an opened LCM?

Finally, does the LCM differ from model to model? Can an '04 LCM be swapped to an '03, and etc. I.E. they aren't tied to PCM codes right?

Given time I may be able to provide much of this info but again right now I don't have it.

This may also help in diagnosing wiper issues people have.

EbonyMarauder03
06-26-2008, 05:02 PM
I will look up what it does in full. I can tell you this, it is one expensive turnsignal flasher.

EbonyMarauder03
06-26-2008, 05:09 PM
I hope this helps

Principles of Operation

The interior lighting can be separated into two distinct modes of operation: the interior lighting and the demand lighting. The lighting control module (LCM) controls all of the interior lighting in the vehicle, as described in the following text.

The front dome lamps, rear reading lamps, and instrument panel interior lamps can be illuminated either by opening any of the vehicle doors (interior lamp function) or by moving the dimmer switch to the dome lamp position (demand lamp function).

When any door is open, the door ajar switch grounds an input to the LCM which then sends power to the interior lamps. The voltage sent to the interior lamps gradually increases from 0 volts to 12 volts within 0.5 second (± 50 milliseconds), to achieve the theater lighting effect. When the door is closed the door ajar switch breaks the ground to the LCM input which then gradually reduces the power from 12 volts to 0 volts within 5 seconds (± 0.5 second).

When the dimmer switch is moved to the dome lamp position it grounds an input to the LCM which in turn sends 12 volts to the front dome lamps, rear reading lamps, and instrument panel interior lamps. When the dimmer switch is moved away from the dome lamp position, it breaks the ground to the LCM input which then ceases to send power to the front dome lamps, rear reading lamps, and instrument panel interior lamps.

The front map lamps, rear reading lamps, glove compartment lamp, vanity mirror lamp, luggage compartment lamp, and engine compartment lamp (police and natural gas vehicles only) are provided with power by the LCM demand lighting output, and are illuminated when a dedicated switch closes, completing the ground circuit for the appropriate lamp(s). As the LCM provides constant power to the demand lamps, there is no ramp up or ramp down time. The illumination is instantaneous once the appropriate switch is closed.

When a door handle is lifted, or a keypad button is pressed, it grounds an input to the LCM which then illuminates the interior lighting using the theater lighting feature. When the unlock button on a remote keyless entry transmitter is pressed, the DDM sends a pulse signal to the LCM which then illuminates the interior lighting using the theater lighting feature. In either instance the interior lamps will extinguish after the time-out using the theater lighting feature. If a lock button on the remote keyless entry transmitter is pressed, or the ignition is turned to the RUN or ACC position, it will extinguish the interior lamps prior to the end of the time-out.

The battery saver will disrupt power to the interior lamps after 10 minutes, the demand lamps after 30 minutes, and the headlamps after 10 minutes. Turning the ignition switch to the RUN or ACC position will terminate the battery saver feature by disabling the interrupt timers and reinstate power to the lamps.

A reset event will set the interior lamps interrupt timer to zero. The reset events for the interior lamps interrupt timer are: turning on the interior lamps by using the dome lamp switch, opening any door (as detected by the door ajar switches).

A reset event will set the demand lamps interrupt timer to zero. The reset events for the demand lamps interrupt timer are: opening the luggage compartment door or opening any door (as detected by the door ajar switches).

When the panic button on a keyless entry remote transmitter is pressed, the panic alarm will override the interior lamps and headlamps battery saver functions for the duration of the alarm.

On police vehicles only, the dark car feature is a special order option that will override the illuminated entry function. If the feature is activated, the courtesy lamps will not illuminate during entry or exit of the vehicle. However, the interior lamps will still illuminate when switched on from the instrument panel dimmer switch.

The unique police instrument panel harness has an in-line connector for enabling or disabling the dark car feature. The in-line connector (C263) is located behind the glove box. When the connection is made, the dark car signal circuit is routed to ground. The feature is enabled by completing the circuit to ground, and disabled by opening the circuit. To enable or disable the feature, disconnect the battery, disconnect or connect C263, and reconnect the battery.

Lighting Control Module (LCM)

The LCM eliminates the electronic interference and heat associated with the thermoelectric devices used previously. The LCM is a microprocessor- based module that controls several vehicle subsystems. It responds to electrical input signals from various switches, sensors, and external modules.

LCM exterior lighting subsystem functions include:

headlamps with autolamps (if equipped)
turn signal lamps/hazard flasher lamps
cornering lamps
parking lamps
battery saver

Breadfan
06-26-2008, 06:18 PM
WOW - This is AWESOME info! This is great! It'll take some time for me digest it, but thanks a bunch for posting that!

xopher
10-28-2009, 11:00 PM
I'm the next contestant on Your Headlights Won't Stay On At Night.

After figuring out where the LCM is and how to bang on it with an Altoids tin, I determined that my intermittent headlights is due to the LCM. I am familiar with the external rely mod developed on crownvic.net (http://www.crownvic.net/ubbthreads/ubbthreads.php?ubb=showflat&Number=1871445&fpart=1). I am considering doing this, but I was also considering replacing the whole LCM myself, as any dealership will charge ~$600-~$800. Buying the LCM alone might cost only $275 (http://www.trademotion.com/partlocator/index.cfm?action=getJointLocat or&siteid=214944). Before I try the advanced board repair option, I was considering getting a used LCM and swapping it in, which leads me to Breadfan's unanswered question, and the reason I chose this thread in particular to bump:

does the LCM differ from model to model? Can an '04 LCM be swapped to an '03, and etc. I.E. they aren't tied to PCM codes right
1) Is the LCM from a 2003 MM the same as a 2004 MM?
2) Is the LCM from a 20XX Crown Vic or Grand Marquis the same as a 2003 MM?

fastblackmerc
10-29-2009, 01:09 AM
I'm the next contestant on Your Headlights Won't Stay On At Night.

After figuring out where the LCM is and how to bang on it with an Altoids tin, I determined that my intermittent headlights is due to the LCM. I am familiar with the external rely mod developed on crownvic.net (http://www.crownvic.net/ubbthreads/ubbthreads.php?ubb=showflat&Number=1871445&fpart=1). I am considering doing this, but I was also considering replacing the whole LCM myself, as any dealership will charge ~$600-~$800. Buying the LCM alone might cost only $275 (http://www.trademotion.com/partlocator/index.cfm?action=getJointLocat or&siteid=214944). Before I try the advanced board repair option, I was considering getting a used LCM and swapping it in, which leads me to Breadfan's unanswered question, and the reason I chose this thread in particular to bump:

1) Is the LCM from a 2003 MM the same as a 2004 MM?
2) Is the LCM from a 20XX Crown Vic or Grand Marquis the same as a 2003 MM?

I believe the LCM's are different between some years and models.

Send me your LCM and I'll put an external relay on it for $25.00. Once installed will look like this.

http://i167.photobucket.com/albums/u133/fastblackmerc/MM%20Mods/LCM%20Repair/DSCN0680.jpg

http://i167.photobucket.com/albums/u133/fastblackmerc/MM%20Mods/LCM%20Repair/DSCN0681.jpg

fastblackmerc
10-29-2009, 01:14 AM
I wanted to start a thread to try and demystify the LCM - Lighting Control Module. Unfortunately, at the present time, I do not have the required info to demystify, so I'll be looking to the community here to help add input.

The first question is this: What specifically does the LCM do, and what specific systems does it interact with?

For instance, does the LCM simply control the automatic headlights? Does in control all lighting, such as interior lights, dimming, turn signal flashing, hazards, headlights, headlights on w/ wipers, headlights on at dusk, etc.

Does it also control other body-related things such as keyless entry, door keypad, etc. How about any other vehicle functions it controls or interfaces with?

Also, does anyone have a pic of it, either in it's location, or pulled out (or both!). Any pics of an opened LCM?

Finally, does the LCM differ from model to model? Can an '04 LCM be swapped to an '03, and etc. I.E. they aren't tied to PCM codes right?

Given time I may be able to provide much of this info but again right now I don't have it.

This may also help in diagnosing wiper issues people have.

The LCM is located right behind and above the OBDI port. Remove a few screws and connectors and you can finagle it out.

Pics of an opened LCM
http://i167.photobucket.com/albums/u133/fastblackmerc/MM%20Mods/LCM%20Repair/03LCMRELAY1of5.jpg

http://i167.photobucket.com/albums/u133/fastblackmerc/MM%20Mods/LCM%20Repair/03LCMRELAY3of5.jpg

http://i167.photobucket.com/albums/u133/fastblackmerc/MM%20Mods/LCM%20Repair/03LCMRELAY4of5.jpg

SC Cheesehead
10-29-2009, 04:33 AM
1) Is the LCM from a 2003 MM the same as a 2004 MM?
2) Is the LCM from a 20XX Crown Vic or Grand Marquis the same as a 2003 MM?

I'll chime in now, and will follow up with some additional info when I get home this evening.

I recently swapped out my LCM with one from a 2004 GM (tip of the hat to RoyLPita for supplying part numbers). The unit works well, but it is a different p/n than the OEM that was in the car. I bought the replacement unit from a salvage yard, but I found out Panther LCMs are a hot item. I contacted a bunch of salvage yards around the country, and those that had '03-'04 Panthers had already sold the LCM's out of them. In fact, one yard up in VA had 2 MM's, but the LCMs out of both were gone. Depending on the particular yard, expect to pay between $50 and $100 (still a whole lot cheaper than a new OEM)

The relay change out will fix your problem, but IMO unless you go with the HD relay, you may have a re-occuring issue. I did a direct replacement with a factory spec relay that I got through Mouser Electronics and that fixed the problem immediately. However, this summer, started having issues again, and the unit failed completely during Marauderville last month. A word on the failure: Banging on the unit will work in most cases and will cause the headlights to come on, but as I found out the hard way, there are a limited number of "bangs" that you can perform before the relay craps out for good. So word of advice. The "bang fix" should be used like a donut spare tire, sparingly...;)

Oh, one last thing. Consider taking fastblackmerc up on his offer. His retrofit is top-notch, and the set-up he uses to re-locate the HD relay gives you easy access to it without removal of the whole LCM.

GordonB
10-29-2009, 06:11 AM
Back to the Orig. Question: Is the LCM for an '03 MM the same as the one for an '04 MM? Not asking about CV of GM, just MMs. Appreciate edumicated feedback.

I now have an '03 MM LCM that needs a new HD relay. Dealer didn't have to ship the old one back under warranty so I got it as a spare to work on.
GordonB

justbob
10-29-2009, 07:21 AM
Many thanks goes out to all of you! My headlights failed to come on the other night for a couple seconds, I heard a click and then they came on. It did this every time I turned them off and on again. But it only did this one night last week.

SC Cheesehead
10-29-2009, 06:53 PM
The LCM that was originally in my car was a 3W7T-13C588-AH. Fastblackmerc did the HD relay retrofit on this one, and I'll swap with out with the current replacement unit if/when I have any problems with the "new" one.

I replaced it with a 4W7Z-13C788-BB that came out of a 2004 Grand Marquis.

I also got the following info from RoyLPita. In addition to the 4W7Z-13C788-BB, a 4W7Z-13C788-BC will work, and these additional p/n's should also be compatable: 3W7Z-13C788-AA, 3W7Z-13C788-AH, 3W7Z-13C788-BA, 4W7Z-13C788-AB, 4W7Z-13C788-BC, or 4W7Z-13C788-BA.

xopher
02-07-2010, 12:31 PM
edit: nevermind for now

xopher
02-09-2010, 09:22 AM
Sorry about the unintentional bump there.

Thanks again for all of the helpful advice here. I almost got the LCM out last night, removing the cosmetic plastic cover, removing the bolts that hold the LCM in its bracket, and unplugged the two gray cables going into the fore-side of the LCM. However, when I removed these two, I was then able to see a third plug, a black plug seating into a white socket. The white socket is the one I'm pointing to with a blue arrow here:

http://i50.tinypic.com/21dokrb.jpg

I had to stop working on it because I was too cold and too late, but I couldn't get the black plug out, and I couldn't find any clips holding it in place. It was pretty cramped quarters and I couldn't even get a pliers on it. I hope I don't have to start disconnecting everything down there to get this thing out. Am I missing something? Any tips?

justbob
02-09-2010, 09:30 AM
If you take out one of the two mounting bracket screws and loosen the other, you can actually "tip" the bracket and slide the LCM out with ease, then disconnect the wires now that you can see them.

Just move the LCM back a little to access the first screw and remove that one (sideways, screwing towards the trans tunnel.)

fastblackmerc
02-09-2010, 10:20 AM
Sorry about the unintentional bump there.

Thanks again for all of the helpful advice here. I almost got the LCM out last night, removing the cosmetic plastic cover, removing the bolts that hold the LCM in its bracket, and unplugged the two gray cables going into the fore-side of the LCM. However, when I removed these two, I was then able to see a third plug, a black plug seating into a white socket. The white socket is the one I'm pointing to with a blue arrow here:

http://i50.tinypic.com/21dokrb.jpg

I had to stop working on it because I was too cold and too late, but I couldn't get the black plug out, and I couldn't find any clips holding it in place. It was pretty cramped quarters and I couldn't even get a pliers on it. I hope I don't have to start disconnecting everything down there to get this thing out. Am I missing something? Any tips?

Disconnect the 2 bottom connectors (usually black, brown or dark grey), disconnect the top connector (usually white), unscrew the 2 gold colored screws (7mm or 8mm) and wiggle out the LCM.

Georges93LX
02-09-2010, 12:36 PM
There is a heavy duty relay available as I have one enroute to me now. It will replace the original on the CB. It was $11.47 + shipping and I get to put it in. The original part from Mouser was on backorder for 16 weeks and another company didn't have any idea when they would have any replacement relays available. If you don't know what you're doing I suggest you send your LCM to fastblackmerc (http://mercurymarauder.net/forums/member.php?u=1670) for the $10.00 special. If your relay is not acting up be ready for it. It's not "IF" but "WHEN".

fastblackmerc
02-10-2010, 10:51 AM
There is a heavy duty relay available as I have one enroute to me now. It will replace the original on the CB. It was $11.47 + shipping and I get to put it in. The original part from Mouser was on backorder for 16 weeks and another company didn't have any idea when they would have any replacement relays available. If you don't know what you're doing I suggest you send your LCM to fastblackmerc (http://mercurymarauder.net/forums/member.php?u=1670) for the $25.00 special. If your relay is not acting up be ready for it. It's not "IF" but "WHEN".

Fixed it..............

fastblackmerc
02-10-2010, 10:52 AM
Sorry about the unintentional bump there.

Thanks again for all of the helpful advice here. I almost got the LCM out last night, removing the cosmetic plastic cover, removing the bolts that hold the LCM in its bracket, and unplugged the two gray cables going into the fore-side of the LCM. However, when I removed these two, I was then able to see a third plug, a black plug seating into a white socket. The white socket is the one I'm pointing to with a blue arrow here:

http://i50.tinypic.com/21dokrb.jpg

I had to stop working on it because I was too cold and too late, but I couldn't get the black plug out, and I couldn't find any clips holding it in place. It was pretty cramped quarters and I couldn't even get a pliers on it. I hope I don't have to start disconnecting everything down there to get this thing out. Am I missing something? Any tips?

The clip for the white connector is on top of the connector. Gotta do it by feel.

fastblackmerc
02-10-2010, 10:54 AM
I'm the next contestant on Your Headlights Won't Stay On At Night.

After figuring out where the LCM is and how to bang on it with an Altoids tin, I determined that my intermittent headlights is due to the LCM. I am familiar with the external rely mod developed on crownvic.net (http://www.crownvic.net/ubbthreads/ubbthreads.php?ubb=showflat&Number=1871445&fpart=1). I am considering doing this, but I was also considering replacing the whole LCM myself, as any dealership will charge ~$600-~$800. Buying the LCM alone might cost only $275 (http://www.trademotion.com/partlocator/index.cfm?action=getJointLocat or&siteid=214944). Before I try the advanced board repair option, I was considering getting a used LCM and swapping it in, which leads me to Breadfan's unanswered question, and the reason I chose this thread in particular to bump:

1) Is the LCM from a 2003 MM the same as a 2004 MM?
2) Is the LCM from a 20XX Crown Vic or Grand Marquis the same as a 2003 MM?

I believe the 2003 & 2004 MM LCM's are interchangeable. Don't know about the CV or GM's ones. They most likely are.

xopher
03-15-2010, 12:31 PM
Thanks again for all of the info. Got my LCM out and about to send it to fastblackmerc for the fix.

Another few questions for anyone who can answer them:
1) I've disconnected my battery while the LCM is out. Do I risk breaking anything reconnecting the battery terminals?

2) EbonyMarauder03's LCM detail was very helpful. Assuming reconnecting the battery isn't harmful while the LCM is out, will the brake lights still work? I was considering moving my MM while the LCM is out, but freeway driving would be sketchy without both turn signals and brake lights.

xopher
03-24-2010, 12:30 PM
Got my LCM back from fastblackmerc Monday and put it all back together last night and the headlights work again!! :D

I highly recommend this for anyone who has issues with headlights not working or cutting out. fastblackmerc saved me HUNDREDS of dollars!

Thanks again, kind sir!! :beer:

fastblackmerc
03-24-2010, 12:45 PM
Got my LCM back from fastblackmerc Monday and put it all back together last night and the headlights work again!! :D

I highly recommend this for anyone who has issues with headlights not working or cutting out. fastblackmerc saved me HUNDREDS of dollars!

Thanks again, kind sir!! :beer:

Glad to help you out!

MrBluGruv
03-28-2010, 05:47 PM
If you take out one of the two mounting bracket screws and loosen the other, you can actually "tip" the bracket and slide the LCM out with ease, then disconnect the wires now that you can see them.

Just move the LCM back a little to access the first screw and remove that one (sideways, screwing towards the trans tunnel.)


Could you elaborate more on this? I just attempted to remove my module and ended up cutting myself up pretty good and getting myself :mad2: off pretty bad. That one cable bundle that plugs into the white socket feels like it's damn near welded into place, I found the pin that holds it in place and could tell i was pressing it down as far as it would go, but it just would NOT budge, and any angle i tried to move the LCM to it wouldn't make a difference, thought I'd worked it to wiggle it out but it just nearly got jammed against the gas pedal.

I'm so upset because this is the only part I can't seem to be able to do, and if i took it to a dealer or a shop to replace it then they wouldn't be doing what I was planning on doing by taking it out myself in the first place.

justbob
03-28-2010, 06:00 PM
You have PM.

Dennis Reinhart
05-03-2010, 08:58 PM
In my honest opinion I feel, LCM should have been a recall, it is a complete safety hazard if we could have contacted the
http://www.nhtsa.gov/ some thing could have been done just as the Mark 8 owners forced Lincoln to make new head lights for the 97/98 Mark 8

Red91LX
06-20-2010, 08:11 PM
The LCM that was originally in my car was a 3W7T-13C788-AH. Fastblackmerc did the HD relay retrofit on this one, and I'll swap with out with the current replacement unit if/when I have any problems with the "new" one.

I replaced it with a 4W7Z-13C788-BB that came out of a 2004 Grand Marquis.

I also got the following info from RoyLPita. In addition to the 4W7Z-13C788-BB, a 4W7Z-13C788-BC will work, and these additional p/n's should also be compatable: 3W7Z-13C788-AA, 3W7Z-13C788-AH, 3W7Z-13C788-BA, 4W7Z-13C788-AB, 4W7Z-13C788-BC, or 4W7Z-13C788-BA.

For what it's worth, a 3W7T-13C788-AH module also came in my '03 300B, built Jan. 07.

dankwun
06-23-2010, 02:24 AM
does the LCM also control the fog lights? My fog lights don't come on anymore and I checked the fuse and its fine. I converted them to HID's so tomorrow I'm gonna hard wire them to the battery and see if they turn on which would only leave me with two options, the switch or the LCM. Unless I am forgetting something that someone might be able to help me with. Any input guys?

fastblackmerc
06-23-2010, 03:48 AM
does the LCM also control the fog lights? My fog lights don't come on anymore and I checked the fuse and its fine. I converted them to HID's so tomorrow I'm gonna hard wire them to the battery and see if they turn on which would only leave me with two options, the switch or the LCM. Unless I am forgetting something that someone might be able to help me with. Any input guys?

Did the foglights work before you converted them to HIDs? If so, it's your installation of the HIDs.

The LCM prolly controls the fogs. If it's the "relay" issue hen you'd have no headlights either.

GENERAL HINT: If your car is working fine and you do some work to it and then it doesn't work, it's most likely the work you just did.

dankwun
06-23-2010, 01:04 PM
the HID fog lights were working fine for about two years. Then one went out and it was a loose wire, so i rewired it and everything was fine for a few months. Then i noticed that neither of them came on anymore, so I checked the wires and everything is fine. I don't see how my wiring would make both of them not work cause they are wired up individually to the wires that the OEM fogs were wired to.. I figure if i wire them straight to the battery and they work then it has to be a switch or relay.. maybe a ground. Idk, i am gonna try this a little bit later and ill let you know what happens.

dankwun
06-23-2010, 08:17 PM
So I wired my fog lights power directly to the fog light fuse and they work now. Just gonna hook them up to a toggle switch. But my headlights are buggin so im thinking my LCM is going. Both lights will work, turn them on and off then only one will work, turn them on and off again the only the other one will work, then do it again and the both work again. LCM?

fastblackmerc
06-24-2010, 05:02 AM
So I wired my fog lights power directly to the fog light fuse and they work now. Just gonna hook them up to a toggle switch. But my headlights are buggin so im thinking my LCM is going. Both lights will work, turn them on and off then only one will work, turn them on and off again the only the other one will work, then do it again and the both work again. LCM?

Are your headlight HIDs?

When the relay in the LCM goes both headlights won't come on.

dankwun
06-24-2010, 08:29 AM
yeaup, they are HID's. I thought that was my problem but i changed the whole conversion kit ..ballasts, wires, and bulbs.. and im getting the same exact problem.

Zack
06-24-2010, 08:57 AM
Just put a relay in the LCM. Costs next to nothing and you can do it in 15 minutes.

fastblackmerc
06-24-2010, 05:00 PM
Just put a relay in the LCM. Costs next to nothing and you can do it in 15 minutes.

If you have the right tools and can solder you can do it.

Did you replace the existing relay or add the external one?

Dennis Reinhart
06-24-2010, 05:36 PM
In my opinion the LCM should have been a recall, this a safety facto and could cause fatalities, the headlights could fail as they did with me at night on a curved road, had I not reacted quickly and pulled back on the dimmer I could have easily run off the road.

dankwun
06-24-2010, 07:23 PM
i have the tools but i dont trust my soldering skills at all.

dankwun
06-24-2010, 07:24 PM
dennis, when you turned the dimmer down the lights came back on?

fastblackmerc
06-25-2010, 04:59 AM
i have the tools but i dont trust my soldering skills at all.

Send it to me.

rrobles
06-28-2010, 07:57 PM
Just put a relay in the LCM. Costs next to nothing and you can do it in 15 minutes.

Yes, Thank you very much too :D hasn't happened anymore. It's a really big relief worrying when and where they are going to go out.

69marquis conv
07-17-2010, 08:05 PM
I did the external relay upgrade this morning in my 04 MGM. Not a difficult job at all, but there's more hassle involved than what fastblackmerc offers to do this task for. If you aren't pushed to turn it around in a day you might want to send it to him.

SC Cheesehead
07-18-2010, 02:57 AM
i did the external relay upgrade this morning in my 04 mgm. Not a difficult job at all, but there's more hassle involved than what fastblackmerc offers to do this task for. If you aren't pushed to turn it around in a day you might want to send it to him.


^^^^^^^+1 ^^^^^^

fastblackmerc
09-20-2010, 07:57 AM
I did the external relay upgrade this morning in my 04 MGM. Not a difficult job at all, but there's more hassle involved than what fastblackmerc offers to do this task for. If you aren't pushed to turn it around in a day you might want to send it to him.

I have acquired 2 spare LCMs. These are ready to be installed. Here is the particulars: http://www.mercurymarauder.net/forums/showthread.php?t=65996

ahess77
10-19-2010, 05:10 AM
There was a NHTSA investigation into this lighting control module that included several model years of this platform. The investigation showed the failure rate did not warrant a recall (all vehicles can have problems, unless the rate is significantly higher than the industry as a whole, then it's not a recall. So thank all the crappy Kia & Hyndai & others for high failure rates.)

You may find that by reflowing the solder around the relay terminals that you can fix intermittant failure of headlamps, turn-signals, cornering lamps, and brake lamps. If you don't know what reflowing the solder means, I wouldn't recommend that you attempt the repair as it takes some skill with the right type of soldering iron not to ruin the board.

The modules are not necessarily interchangeable, upgrades were made and implemented at model year or as running changes.

fastblackmerc
10-19-2010, 05:16 AM
There was a NHTSA investigation into this lighting control module that included several model years of this platform. The investigation showed the failure rate did not warrant a recall (all vehicles can have problems, unless the rate is significantly higher than the industry as a whole, then it's not a recall. So thank all the crappy Kia & Hyndai & others for high failure rates.)

You may find that by reflowing the solder around the relay terminals that you can fix intermittant failure of headlamps, turn-signals, cornering lamps, and brake lamps. If you don't know what reflowing the solder means, I wouldn't recommend that you attempt the repair as it takes some skill with the right type of soldering iron not to ruin the board.

The modules are not necessarily interchangeable, upgrades were made and implemented at model year or as running changes.

Reflowing the solder may not fix the headlight / relay issues as the relay is undersized for the amount of amps flowing through it. Most of the LCM's that I've repaired have a brown spot on the pcb which is caused by the relay getting too hot. IMHO, an external heavy duty relay is the only way to go.

TFB
10-19-2010, 07:56 AM
The modules are not necessarily interchangeable, upgrades were made and implemented at model year or as running changes.

Everything I've seen says the '03-'04 LCMs are interchangeable and that includes the CV & MGM as well... Earlier or later ones do not...

fastblackmerc
10-19-2010, 08:12 AM
Attached is a spreadsheet with some of the Ford LCM revisions for current models.

mbmast
05-01-2013, 06:01 PM
I'm having some very strange problems that I originally thought were LCM related (I'll describe those below). I pulled the LCM and desoldered all 4 relays and replaced them with brand new relays (4 new [COLOR=black][FONT=&quot]EQ1-11111S relays). I reinstalled the LCM and nothing had improved.

Thinking perhaps the LCM had a problem with another component (or components) other than the relays, I replaced the entire LCM with a brand new one (4W7T-13C788-BC). Still, no improvement. So my problem is not the LCM.

Here are the symptoms:

1. Headlights flash on when in the off position.
2. Headlights turn off when in the on position. "Off" can last for up to an hour while driving, so no driving this puppy at night until this is resolved.
3. Turn signals go out and then sometime later start working again.
4. The overhead lights (interior) sometimes don't work, but usually they do.
5. The horn goes off for a fraction of a second occasionally.
6. The battery tends to go dead. It is a brand new battery (less than 500 miles on it).

All of these problems started when the NEW ENGINE was installed.

Is this a wiring harness problem? If so, where would I start looking and what would I be looking for?

Thanks.

fastblackmerc
05-01-2013, 07:33 PM
I'm having some very strange problems that I originally thought were LCM related (I'll describe those below). I pulled the LCM and desoldered all 4 relays and replaced them with brand new relays (4 new [COLOR=black][FONT=&quot]EQ1-11111S relays). I reinstalled the LCM and nothing had improved.

Thinking perhaps the LCM had a problem with another component (or components) other than the relays, I replaced the entire LCM with a brand new one (4W7T-13C788-BC). Still, no improvement. So my problem is not the LCM.

Here are the symptoms:

1. Headlights flash on when in the off position.
2. Headlights turn off when in the on position. "Off" can last for up to an hour while driving, so no driving this puppy at night until this is resolved.
3. Turn signals go out and then sometime later start working again.
4. The overhead lights (interior) sometimes don't work, but usually they do.
5. The horn goes off for a fraction of a second occasionally.
6. The battery tends to go dead. It is a brand new battery (less than 500 miles on it).

All of these problems started when the NEW ENGINE was installed.

Is this a wiring harness problem? If so, where would I start looking and what would I be looking for?

Thanks.

Need to check ALL the harnesses and connectors in the engine compartment.

I bet there is a ground or two that is missing, loose or dirty.

bugsyc
05-03-2013, 04:17 AM
I don't see the fog lights mentioned in the functions of the LCM...Are they a seperate circuit that doesn't go thru the LCM??

fastblackmerc
05-03-2013, 05:45 AM
I don't see the fog lights mentioned in the functions of the LCM...Are they a seperate circuit that doesn't go thru the LCM??

Foglights go from the foglight relay in the power distribution box under the hood, through the multifunction switch and the LCM.

bugsyc
05-03-2013, 05:52 AM
Which relay in power dist. box?207? Multi function switch or headlight switch?

fastblackmerc
05-03-2013, 05:53 AM
Which relay in power dist. box?207? Multi function switch or headlight switch?

Check the owners manual.

drgnrdr33
10-01-2014, 04:53 PM
Attached is a spreadsheet with some of the Ford LCM revisions for current models.

I think I just stumbled onto the spreadsheet that used to be in your post...

Mr. Quipster
10-06-2014, 04:36 PM
Forgive me if this info is already out there, but I bought a used Marauder (The Baddest Panther) recently and the headlights sometimes wouldn't come on.

I did a little sleuthing and found out the lighting control module was the culprit and it's a $500 part. Boo!

I did a little more sleuthing and found out if your Panther is less than 15 years old and has less than 250k miles, Ford with replace the LCM for free.

Had it done last week. Sweet!

RF Overlord
10-06-2014, 06:11 PM
Posted here many times, but thanks...

MyTMerc
11-06-2014, 07:14 PM
I've been reading through the headlight posts trying to find a similar issue. My driver's side headlight is intermittently dimly lit or not at all. I replaced the bulb with a Silver Star and had the same issue. It seems like the LCM failure would affect both but not just one?

It looks like only the top half of the bulb is dimly lit.

I'll be checking for a bad ground after the ABT event this weekend. Has anyone had a similar issue? Ideas?

Background: The headlights and front grill, bumper etc. were replaced earlier in the year after a minor altercation with a Jersey wall in Michigan. We haven't put many miles on it since, very minimal night driving mainly back in June at Carlisle.

fastblackmerc
11-07-2014, 05:20 AM
I've been reading through the headlight posts trying to find a similar issue. My driver's side headlight is intermittently dimly lit or not at all. I replaced the bulb with a Silver Star and had the same issue. It seems like the LCM failure would affect both but not just one?

It looks like only the top half of the bulb is dimly lit.

I'll be checking for a bad ground after the ABT event this weekend. Has anyone had a similar issue? Ideas?

Background: The headlights and front grill, bumper etc. were replaced earlier in the year after a minor altercation with a Jersey all in Michigan. We haven't put many miles on it since, very minimal night driving mainly back in June at Carlisle.
Highly doubt the problem is LCM related. If it was, both headlights would be affected.
Sounds like a "ground" or pinched wire issue.

RF Overlord
11-07-2014, 08:04 AM
What FBM said.

lji372
11-07-2014, 11:17 AM
what rf said

Blaine B.
12-16-2014, 08:04 AM
In my opinion, there is nothing worse than the "door handle activated lights" that activate if one of the two front door handles is lifted, even if the doors are locked. Essentially giving potential thieves the abilitity to see in your car, even through window tint. Such a bad feature!

I disabled this feature on my car by disconnecting Pin 12 in the C2027 plug on the PCM. I believe that you can also remove the door panels and disconnect the plug from the door handles directly.

You can disable this feature, yet still have the interior lights turn on when the doors are opened. Now, that makes complete sense, and will be like the majority of cars on the road.

jmsa540
12-24-2014, 05:23 PM
I'll go ahead and add something to this thread..

Today while driving, my battery light came on and quickly went off, it was literally less than two seconds.

Now, question, when your auto lights come on and you manually turn the switch to off, they still stay on until it gets brighter outside (sunlight) then they manually turn off. I can at anytime turn my headlights on and off manually (once the auto lights are turned off)

What is this?

Blaine B.
12-24-2014, 05:26 PM
That doesn't sound right. The only time the headlights should still stay on when in the "off" position is if the car had factory daytime running lights (highbeams with low power) or was custom wired to have the headlights stay on all of the time, like how some US cars are wired for importation into Canada.

jmsa540
12-24-2014, 06:53 PM
yeah, I was kinda thinking the same thing?

can anyone else test this theory for me on their car?

Blaine B.
12-24-2014, 06:58 PM
The closest that I have come to the headlight switch style in your Marauder was in a 2010 Grand Marquis with auto lamps and daytime running lamps.

When in the "off" position, all of the marker lights and headlights turned off, but the high beams remained on with limited voltage (dim.)

In my 2001 which originally had auto lamps, no lights were on when the switch was in the off position. My 01 also had wiper activated headlights, though, which I disabled by snipping the wire between the LCM and the wiper control module.

jmsa540
12-24-2014, 07:09 PM
Correct, no lights are on in the off position UNLESS the lights were ALREADY on when on AUTO lights.

Blaine B.
12-24-2014, 07:10 PM
Right, but that doesn't sound right, because they should always totally turn off when switched to off, unless you have wiper activated headlights (and the wipers are on) or you have daytime running lights.

Are just your headlights on, or all of the marker lights too?

Here's another post from over a year ago with another Marauder owner who has his auto lamps turning on and off even when the switch is in the OFF position. Even more strange than your issue.

http://www.mercurymarauder.net/forums/showthread.php?t=89750

jmsa540
12-24-2014, 07:18 PM
When they're in the off position they stay on until they turn off by themselves, then they never come back on again unless I manually turn them on, etc.

Hey, also, thanks for replying to me.. means a lot.

Blaine B.
12-24-2014, 07:19 PM
Sounds like a similar-but-different problem for the both of you. Wonder if it relates to the LCM or the headlight switch itself.

But as I asked, are these just your headlights that stay on, or the headlights AND marker lights/tail lights?

jmsa540
12-24-2014, 07:20 PM
Now that I think about it, my wipers were on all day today.. perhaps that's the issue?

I take it that our lights come on with the wipers on? Or am wrong?

jmsa540
12-24-2014, 07:23 PM
Blaine, reading that thread you gave me is down right weird.. that's crazy.

Blaine B.
12-24-2014, 07:24 PM
Previously, yes....whenever I switched the wipers on, after about 30 seconds, the lights would kick on. I snipped the wire and insulated it, which runs between the wiper module and the LCM. Not all cars have this feature, though, and it didn't matter if my switch was in the auto lamps mode or not. It may have only been 2001 models, or 2001-2002. I have never seen this feature on another Panther platform car, and one of my friends has owned about a dozen of them over the years.

I also snipped the wire that would illuminate the interior lights if the door handles were lifted, regardless if the doors were locked or not. Seemed like a good way for thieves to look inside the car. Now, the lights only illuminate when the doors are actually opened. If they are locked and you pull the handle, nothing lights up anymore.

jmsa540
12-24-2014, 07:33 PM
nice! I like that, that's good thinking, man.

Blaine B.
12-24-2014, 07:34 PM
I haven't seen all cars have the door handle "courtesy" function, either. Does yours? If the doors are locked and the exterior handle is pulled, that is.

jmsa540
12-24-2014, 08:50 PM
let me check, then get back to you, brother...

jmsa540
12-25-2014, 10:18 AM
Pulled up on the doorhandle, lights done come on.

Blaine B.
12-25-2014, 10:22 AM
Is that a do, or don't?

It would only apply to the front two doors, not the rear doors.

fastblackmerc
12-25-2014, 11:28 AM
Now that I think about it, my wipers were on all day today.. perhaps that's the issue?

I take it that our lights come on with the wipers on? Or am wrong?

Yes the light will automagically come on when the wipers are on.

Blaine B.
12-25-2014, 12:21 PM
http://www.idmsvcs.com/2vmod/wipersonlightson/index.html

You can use this diagram to find the appropriate wires to "snip" and insulate, to deactivate the wiper-activated headlights and/or door handle activated interior lights.

Be aware, when I went through this process on my 01, the wire colors did NOT match up. The color of the LCM plugs also did not match up. For instance, they mention two black plugs and one grey plug. On my car, there was one black plug and two grey plugs.

However, the size of the plugs and the pin numbers and locations were all the same, so that is how I was able to locate the appropriate wires in my car.

jmsa540
12-25-2014, 11:11 PM
don't, sorry.

jmsa540
12-25-2014, 11:11 PM
I wonder what would've caused my battery light to come on for a brief second then turn back off?

Blaine B.
12-26-2014, 08:09 AM
Maybe a dirty ground somewhere, intermittent failing alternator, dirty and/or loose battery terminals, or failing battery?

fastblackmerc
12-26-2014, 09:55 AM
I wonder what would've caused my battery light to come on for a brief second then turn back off?
If it happens again I'd worry about it.

chief455
12-26-2014, 11:32 AM
I wonder what would've caused my battery light to come on for a brief second then turn back off?

what rpm was your engine at when this happened?
My batt light has blinked for a second right when my car nearly stalled / idle too low - many cars I've seen do this.

TJCOX
12-27-2014, 10:55 AM
A recall was initiated and I had a Ford dealer replace it in about fifteen minutes!

fastblackmerc
12-27-2014, 09:49 PM
A recall was initiated and I had a Ford dealer replace it in about fifteen minutes!

Was it an LCM or the "Dorman" fix?

jmsa540
12-28-2014, 12:19 AM
what rpm was your engine at when this happened?
My batt light has blinked for a second right when my car nearly stalled / idle too low - many cars I've seen do this.

It's funny you say this, I believe my car's idle just got too low. Sometimes I look at the scangauge and every now and then it dips down to 520+/- rpms

TJCOX
12-28-2014, 01:14 PM
Was it an LCM or the "Dorman" fix?

MOTORCRAFT PART # 4W7Z-13C788-BC PROCESSOR-LIGHTING CONTROL (MESSAGE: CRITICAL)

SHIPPED FROM: NEW YORK HVC, 280 PROSPECT PLNS RD, CRANBURY, NJ 08512

CAUSE:E 14N01C AUTH CODE: 008932

MyTMerc
01-21-2015, 10:34 AM
I've been reading through the headlight posts trying to find a similar issue. My driver's side headlight is intermittently dimly lit or not at all. I replaced the bulb with a Silver Star and had the same issue. It seems like the LCM failure would affect both but not just one?

It looks like only the top half of the bulb is dimly lit.

I'll be checking for a bad ground after the ABT event this weekend. Has anyone had a similar issue? Ideas?

Background: The headlights and front grill, bumper etc. were replaced earlier in the year after a minor altercation with a Jersey wall in Michigan. We haven't put many miles on it since, very minimal night driving mainly back in June at Carlisle.
Just to follow up on the resolution of this problem. After much troubleshooting, I found there were several problems. My new Ford buckets were replaced at the body shop during the repair of the front end plastic with a cheaper aftermarket version of the bucket and harness assembly. My Silver stars were also replaced with cheap bulbs. Both of these components seemed to contribute to the lighting issues. I replaced the bulbs and got rid of the extremely dim lights but still had the intermittent on off problem. I found a loose wire at the bulb connector on the passengers side and loose pins at the other end of the harness pigtail on the drivers side. Comparing the aftermarket harness to a new Ford harness, the Ford harness was taped (wrapped) together inside the flexible plastic wire protector and outside the flex tubing as well. The aftermarket harness was just threaded through the flex tubing and was loose inside causing the two ground wires and pins to move freely. I was able to jiggle the harness and re-create the problem. So, the fix was to remove the flex tubing protecting the harness and securely tape (wrap) the wiring which helped the pins remain in the stable position. I re-installed the flex tubing around the wires and taped them up completely like the factory harness. No free movement of the wires equaled no intermittent lighting problem.

RF Overlord
01-21-2015, 02:33 PM
Nice save, brah. Your repairer probably billed the insurance company for OEM, but obviously used cheap crap.

haro.john
01-17-2016, 10:00 AM
This quite possibly could be the right thread that I'm looking for. I am currently trying to figure out why the windshield wipers do not work. I took off the windshield wiper regulator and ran power to the motor the motor is good the regulator I'm not sure. I also replace the switch and still no wipers. I'm thinking LCM, since there's a recall on the vehicle. I'll bring it in Monday and let you guys know if that was my problem.

Sent from my SM-N915T using Tapatalk

fastblackmerc
01-17-2016, 10:36 AM
This quite possibly could be the right thread that I'm looking for. I am currently trying to figure out why the windshield wipers do not work. I took off the windshield wiper regulator and ran power to the motor the motor is good the regulator I'm not sure. I also replace the switch and still no wipers. I'm thinking LCM, since there's a recall on the vehicle. I'll bring it in Monday and let you guys know if that was my problem.

Sent from my SM-N915T using Tapatalk

What do you mean by the regulator?

When you detached the wiper motor did you try to move the wipers to see if they are OK? Sometimes the linkage is bound up or bad.

Are you getting power to the motor?

The LCM recall is for a no low beam condition. Ford won't replace it for wipers not working.

haro.john
01-17-2016, 11:30 AM
I believe I read that the LCM also controls something to do with the windshield wipers. Pic is regulator.

http://uploads.tapatalk-cdn.com/20160117/5643933185037931eb21a396c4a0f0 8e.jpg

Sent from my SM-N915T using Tapatalk

haro.john
01-17-2016, 11:31 AM
What do you mean by the regulator?

When you detached the wiper motor did you try to move the wipers to see if they are OK? Sometimes the linkage is bound up or bad.

Are you getting power to the motor?

The LCM recall is for a no low beam condition. Ford won't replace it for wipers not working.
The linkage is good to go.

Sent from my SM-N915T using Tapatalk

fastblackmerc
01-17-2016, 11:34 AM
I believe I read that the LCM also controls something to do with the windshield wipers. Pic is regulator.

http://uploads.tapatalk-cdn.com/20160117/5643933185037931eb21a396c4a0f0 8e.jpg

Sent from my SM-N915T using Tapatalk

Yes, the wipers tell the LCM to turn the headlights on after the wipers have been on for a specified amount of time ---- note: that time is not adjustable by the driver.

haro.john
01-17-2016, 11:39 AM
Low beams are operable, I'm going to go out right now with a test light. To check power from fuze box, and at motor regulator.

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