PCM programming and Traction Control

[TripleTransAm]

I haven't had a chance to dig through the manuals yet, but I was wondering if anyone had stumbled across this info yet, while digging through all the programmable PCM parameters.

Is it possible to reprogram the front/rear ratio of wheel rotation that the traction control expects to see? In other words, is it possible to program the PCM (or whatever module) to accept equal sized tires front and rear AND maintain a functional traction control?

This came into my mind during tonight's blizzard as I thought about how traction control was offered on other Panther cars. Since those cars have 4 same sized wheels/tires all around, it must be something programmable in order to make it useable for the Marauder's offset wheel/tire sizes.

[DetGeno]

I'll be interested in knowing this as well?

[gilby04]

DetGeno,
Where did you purchase your SuperChip's MicroTuner ?
And at what price ?
Thanks,
Jim

[JohnE]

I seriously doubt the nominal difference in hub rotation between the front and rear axles makes a difference to the ABS Computer. Impeding wheel slip is mainly a rate change to detect. And to top this off, the Marauder is allowed more wheel slip than other Panthers before Traction Control intervention.

IIRC the amount of Traction Control timing retard is an adjustable parameter with a chip. However the actual traction control detection parameters are stored in the abs computer, not changeble with a chip.

John

[joflewbyu2]

YES, with a 2003 MM use the Superchips tuner and program the rear to 3.73 (stock is 3.55 + 5% [.1775] = 3.7275) which is 5% numerically higher which corresponds the same as a 235/50 vs 245/55 which is 5% smaller rolling distance.

[TripleTransAm]

Brilliant solution, mr.flewbyme. Interesting approach, I will investigate the options with other winter tire solutions and hopefully one of them will work out right. Thanks again for the great thinking. :up: :up:

[mtnh]

The traction control is mainly monitored and implemented on the ABS/TC processor module, which sits under the ABS pump/valve body assembly. The PCM just uses pullback info as requested by the ABS/TC processor, when less throttle is needed. This info was privately provided to me from a former contributor to the forums, Brian, an engineer who oversaw the buildability of the MM at Ford and was quite helpful in these areas (as well as the original subwoofer rattle fix thread).. He knew the entire car. From what I heard, using the same size tires all around on the MM places the system into a marginal, yet functional state, so actually, no programming should be necessary.

Mike

[SergntMac]

Originally posted by mtnh
From what I heard, using the same size tires all around on the MM places the system into a marginal, yet functional state, so actually, no programming should be necessary. Mike

Using the same size tires at each corner is okay?

If I wanted to install 245/45/18 on the front and 245/45/18 on the rear, this will not trigger any alarms?

I have to ask...What does send an alarm?

What are the limitations in front/rear size differences?

[DetGeno]

gilby04 - I've got mine SuperChips MicroTuner from Dennis Reinhart at a very reasonable price and a satisfaction guarantee or he'll take it back. IMHO for all 300A's it's not a big deal to have all the same tire sizes but for all 300B's with traction control with all the same size will trigger the traction control to come on around 25MPH and you have to turn the TC off. It's a pain in the A$$.

[mtnh]

I had read on MM.net that some folks with 300B 2003 MM had gone to 4 tires that matched the same size and had no issues with traction control, but if there is an update to that, then I would respect that info. From my earlier understanding, four tires the same size front and rear place the t/c right at the threshold of flagging an error condition.

Mike

[TJH]

Great discussion! I was actually thinking about putting the rear-sized tires up front, to better fill the front wheel openings. Also, it would add a bunch to the sidewall height, which would help to handle the spring Michigan potholes-from-hell.
Now, what I'd REALLY like, is a couple of 235-wide, 55-series aspect ratio BFG's to match the rears...
I'll have to see if the 245-55's will fit during full-lock steering and full jounce/rebound conditions...

[ModMech]

It is my understanding that the logics look for a "rate of relative change", and not at the absolute differences.