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Old 10-18-2013, 09:48 PM   #252 (permalink)
t vago
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Originally Posted by RobertISaar View Post
depending on how sophisticated your PCM/TCM is, it might work to stop codes using a resistor.
After reviewing the FSM for my car, I see that my PCM (which happens to also control the transmission - Chrysler combined the two modules into one around 2003, I think) is ridiculously sophisticated. The stupid thing actually looks for the flyback voltage that is generated after a pulse is sent to each solenoid. A resistor would not work, I think. It's like when I tried to fool the PCM into thinking that my EGR valve was less open that it really was. The darned thing actually measures current draw, and throws a code if it sees an excessive resistance through the EGR position sense circuit.

Originally Posted by RobertISaar View Post
others aren't so easily fooled. they'll expect to see slip at times and if it isn't present, will start throwing codes that may or may not trigger the SES lamp.
I don't mind seeing a SES lamp - Indeed, I lived with one for almost two years with my truck, because I installed a slightly newer TCM in that beast that was almost completely electrically compatible (it came out of a Jeep Grand Cherokee) and that "added" a 2nd overdrive, but that could not communicate with the rest of the truck electronics because it used a newer and incompatible vehicle network (PCI vs. Chrysler Collision Detection).

On the other hand, I do very much mind if the PCM were to actually go into a limp-in mode that actually caused more fuel to be consumed than normal.
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