I'm having problems with "charge systrm faults" and I think the PCM may be the issue.

 

TTT

 

Quite some time ago I read here on the forum that all computers must match to your car and should be programmed as such. They kinda communicate with each other so options and VIN number must match.

Roger :cheers:

 

:yesnod: Yes,it will have to be programmed...

 

Did you consider replacing the battery first? You get that error if the voltage is low - usually right after you start the car and it is at idle (before the batt recharges).

If you replace the PCM, the car will not start until you either sync it up using a Tech -II or go thru this painful on-off-on-off-on-off key sequence. The PCM is locked down for security reasons (?).

If you are essentially stock, and get a PCM for the same model year, you should be able to use the PCM without programming. C5-Tech, correct me if I mispoke.

F

 

SLICKMAN,

I don't know about the PCM - but here is some related advice.

I had repeated "charge system fault" messages on the DIC of my 1999 C5 coupe. The dealer was stumped and called Chevrolet Technical Assistance. They instructed him to check/clean several ground locations on and near the starter (under the battery tray). He found the locations and cleaned and tightened the nuts (the nuts were loose). That eliminated the messages.

This was not from acid leaking from my Delco battery (but that did occur later).

My car was purchased new and is never driven in the rain or stored outside. The mechanic said that Technical Assistance immediately knew what the problem was and it must be common because they knew about the problem and fix.

Good luck. I hope this helps.

PS - My 1999 has the Firethorn interior also.

 

The last time I was under there (about two weeks ago) everything looked good and tight. I'm going to get back under there and take every connection off the starter and make sure its cleaned and put back in place. The ground that is under the battery I did take apart, clean an reinstall. My battery is a new optima and the alternator is new as well.

It seems each time I have made a repair, the problem seems to get better but not a total fix. I'm getting closer and with everyones help I hope to fix this little devel..

 

"If you replace the PCM, the car will not start until you either sync it up using a Tech -II or go thru this painful on-off-on-off-on-off key sequence. The PCM is locked down for security reasons (?)."

I replaced my PCM, started the car and drove it. Very simple install and no special relearn procedures.

Bob
:flag

 

You will need a VATS re-learn!!!!!!!!!!!!!!!

 

The PCM will do a relearn while driving. That is my experience when I changed mine. Or am I missing something?

Bob
:flag

 

My experience is that the car would fire once and die, until you performed the VATS relearn. This can be accomplished using a Tech-II or by performing a time-intensive manual relearn.

Did you get a brand new PCM, or did you get it reflashed/reprogrammed? PCMs are mated to the chassis as part of the security system.

F

 

No not yet, I was going to get it from GMParts Direct...

 

I bought a new PCM from the tuner and he programmed it and sent it to me. I installed it and drove the car. No problems, no special relearn procedures. I have no idea why you would have to do all the extra relearn procedures. Mine is a new '03 C5 if that would make a difference.

Bob
:flag

 

Thats a thought, who did you get yours from?

 

If you simply have your PCM programmed then you are OK. Using a completely different PCM will require the VATS re-learn....this is the security system. The car will not run without the re-learn. A Tech II can be used or it can be done manually. Here it is:

Important
The body control module (BCM) must be programmed with the proper RPO configurations before performing learn procedures. Refer to BCM Programming/RPO Configuration .
If replacing the BCM with a GM Service Parts Operations (SPO) replacement part, the module will learn the passkey data code immediately. The existing PCM however, must learn the new fuel continue password when the BCM is replaced.
If replacing a PCM with a GM Service Parts Operations (SPO) replacement part, after programming, these modules will learn the incoming fuel continue password immediately upon receipt of a password message. Once a password message is received, and a password is learned, a learn procedure must be performed to change this password again. A PCM which has been previously installed in another vehicle will have learned the other vehicle's fuel continue password and will require a learn procedure after programming to learn the current vehicle's password.

Conditions
Use these procedures after replacing:

BCM
PCM

10 Minute Learn Procedure

Tools Required
Tech 2
Techline terminal with current SPS (Service Programming System) software
Connect the Tech 2 to the vehicle.
Select "Request Information" under "Service Programming".
Disconnect the Tech 2 from the vehicle and connect it to a Techline terminal.
On the Techline terminal, select "Theft Module Re-Learn" under "Service Programming".
Disconnect the Tech 2 from the Techline terminal and connect it to the vehicle.
Turn ON the ignition, with the engine OFF.
Select "VTD Re-Learn" under "Service Programming".
Attempt to start the engine, then release the key to ON (vehicle will not start).
Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF (the vehicle is now ready to relearn the password on the next ignition switch transition from OFF to CRANK).
Turn OFF the ignition, and wait 5 seconds.
Start the engine (the vehicle has now learned the password).
With the Tech 2 (scan tool), clear any DTCs.


30 Minute Learn Procedure

Turn ON the ignition, with the engine OFF.
Attempt to start the engine, then release the key to ON (vehicle will not start).
Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF.
Turn OFF the ignition, and wait 5 seconds.
Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes (the vehicle is now ready to relearn the password on the next ignition switch transition from OFF to CRANK).

Important
The vehicle learns the password on the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.


Start the engine (the vehicle has now learned the password).
With a scan tool, clear any DTCs if needed (history DTCs will self clear after 100 ignition cycles).

 

This is the guy I bought mine from and he programmed it. I installed it, started the car and started driving.
http://westers_garage.eidnet.org/

Bob


:flag

 

SLICKMAN,

One additional "tip": Someone recently posted information about the "charge system fault" message and stated that they removed a lower shield under the computer in the right front of the car (behind the right front wheel and under the battery tray). They found leaves and "junk" that were bunched up around the wiring harness attached to the computer. The debris was removed and the wiring cleaned and dryed. That also eliminated the messages.

I hope this helps. Good luck.

 

Yep, that was me :lolg: I thougth it was solved at that point but I was wrong.. Its better but not gone.

 

"If you simply have your PCM programmed then you are OK. Using a completely different PCM will require the VATS re-learn....this is the security system. The car will not run without the re-learn. A Tech II can be used or it can be done manually. Here it is:"

That's not true. I put in a new PCM, started the car and drove it. Read my previous threads.

Bob
:flag

 

Hmmmm, My car required the VATS re-learn when a new PCM was used and that was told to me and the tuner by Ed Wright. Oh well.....guess the cars are different.
[Modified by Buckmaster, 2:04 PM 8/19/2003]