Moparchat - Home of MOPAR enthusiasts worldwide!

Moparchat - Home of MOPAR enthusiasts worldwide! (http://www.moparchat.com/forums/index.php)
-   Dakota Truck Forum (http://www.moparchat.com/forums/forumdisplay.php?f=52)
-   -   You can't reset your PCM by unhooking your battery (http://www.moparchat.com/forums/showthread.php?t=12178)

jamckimmey 02-08-2001 04:19 AM

I found this out this weekend. I took my truck in to try to get the idle sag flash but is was only for 2000's. He said he would reset my PCM for me since I installed a Z-tube and starting over was better than learning. I asked him if all you had to do was disconnect the battery and he said no you have to have it done by their computer. This hold true on 96 and newer dakotas he said. This guy is a certified dodge master tech and has all his patches (13?). He is a good friend and is not trying to make money for the dealership. It seems to have helped in the idle sag a little but I'm still waiting for the TSB for the 2001's. Just a little information I found out, not trying to prove anybody wrong or anything.

2001 reg cab sport plus
4.7 V8 5 speed
3.92 limited slip
Z-tube

FasstDak 02-08-2001 05:35 AM


Cough...cough...bull...hack...sh--...cough...

If you disconnect the battery, hold the ignition in the START position for 15-20 seconds, release the key, and then reconnect the battery...the system is reset.

Done this on too many Dodge's for him to say otherwise. Textbook learning is wonderful...but there ARE alternative methods. Having all the patches doesn't mean that someone's a good mechanic. From my life int he shop days, I met up with plenty of "Book Worm" mechanics who could pass all the tests...but couldn't do anything without their textbooks either.

Nothing against your buddy though.

FasstDak 02-08-2001 06:27 AM

Here's something for your mechanic friend to pass around. It's part of their testing/education:

------------------------------------------
United States
Environmental Protection Agency
EPA420-P-00-006
December 2000

Performing Onboard
Diagnostic System
Checks as Part of a Vehicle
Inspection and Maintenance Program


There are several reasons why a vehicle may arrive for testing without the required
readiness codes set. These reasons include the following:

1) Failure to operate the vehicle under the conditions necessary to evaluate the
monitor(s) in question;

2) A recent resetting of the OBD system due to battery disconnect or replacement, or
routine maintenance prior to testing;

3) A unique, vehicle-specific OBD system failure;

4) An as-of-yet undefined system design anomaly; or

5) A fraudulent attempt to avoid I/M program requirements by clearing OBD codes just
prior to OBD-I/M testing (by, for example, temporarily disconnecting the battery).

Because unset readiness codes could be a sign of attempted fraud, it is important that all OBD-equipped vehicles be checked to confirm that readiness codes have been set as one of the pre-requisites for a valid OBD-I/M inspection. Nevertheless, as described in the NPRM, EPA also believes that the current requirement regarding readiness codes (i.e., that a vehicle be rejected from further testing if any monitor is found to be “not ready”) is more rigorous than is
necessary or practical. Therefore, as discussed under “Basis for Failure or Rejection” above, EPA has proposed to revise the current readiness requirement to allow states to complete the testing process on MY 1996-2000 vehicles with two or fewer unset readiness codes; for MY 2001 and newer vehicles, the testing process could still be complete provided there is no more than one unset readiness code. This does not mean that these vehicles are exempt from the
OBD-I/M check. The complete MIL check and scan must be run in all cases, and the vehicle still must be failed if any of the failure criteria discussed in this draft guidance are met. The vehicle should continue to be rejected if it is MY 1996-2000 and has three or more unset readiness codes or is MY 2001 or newer and has two or more unset readiness codes.
----------------------------------------

You can reset your PCM with the disconnect battery method. (Read

Zeus 02-08-2001 07:43 AM

I have to say that your friend is misinformed also, I'm not trying to made you mad or anything but I know from personal experience that it works, I have done the reset deal on my R/T 2 or 3 times at least.


jamckimmey 02-08-2001 08:16 PM

O.K. Next question. How do you know when your PCM has been reset if you do not have a dodge diognostic (spelling?) computer?

Just trying to get to the botom of this.

musclebound 02-08-2001 10:10 PM

Does resetting the pcm with out the OBD mess with the pcm... ? Does it reset the perf. pcm to stock settings? Or does it reset the check engine light.. from let say bad O2 readings from running open headers... http://www.moparchat.com/ubb/smile.gif

FasstDak 02-09-2001 08:37 AM

On the finding out if it's been reset, you use the Key-ON-OFF method and, if the PCM has lost power within the last 50-cycles, it will have a code. (12 I think)

OBD stands for On Board Diagnostics. It's the actual system that your PCM uses: OBD-I, OBD-II, and the up and coming OBD-III. Resetting it won't hurt anything. Resetting the PCM will not remove any of the Mopar Performance Tables either. On the "Check Engine Light", it will reset the light as well but if there's a problem, the light will come on after 3 cycles.

- Bernd


All times are GMT -4. The time now is 07:26 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.