2002 Cavalier finally running but with new problems. Please Help

05-21-2011, 08:25 PM
Ok here we go. After replacing the PCM in my sons 02 cavalier we could not get it started. After countless hours of research we took it to the dealer. Even they could not get it to start. They told us it was because we did not have a stock radio witch I do not understand because it ran before with the radio that is in it.Anyways, I finally got it to run using the below procedure.

1. Turn ON the ignition, with the engine OFF.

2. Attempt to start the engine, then release the key to ON (vehicle will not start).

3. Observe the SECURITY telltale, it will be flashing. After approximately 10 minutes the telltale will turn OFF.

4. Turn OFF the ignition, and wait 5 seconds.

5. Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes. The vehicle is now ready to relearn the PASSlock Sensor Data Code and/or passwords, on the next ignition switch transition from OFF to CRANK.

IMPORTANT: The vehicle learns the PASSlock Sensor Data Code and/or password on the next ignition switch transition from OFF to CRANK. You MUST turn the ignition OFF before attempting to start the vehicle.

6. Start the engine. The vehicle has now learned the PASSlock Sensor Data Code and/or password.

7. With a scan tool, clear any DTCs if needed. History DTCs will clear themselves after 100 ignition cycles.

I now have new problems.

#1 The following gauges stay lit.
Check gauges
Trac Off
Check Engine

#2 I can not shift it with my foot on the break.

#3 Fuel gauge does not work.

#4 Radio does not work

DTC's are as follows, I erased them once and drove the car down the road a little ways and they came right back.


Any help or insight to these problems would be greatly appreciated.

Thank you,

05-29-2011, 05:34 PM
I believe the PCM on these needs to be programmed prior to operating the vehicle. Did you tell the dealer you replaced the PCM? Did you install a new PCM or a salvaged one? A salvaged one cannot be used without special software. The PCM is configured to the vehicle, and the Tech2 (the GM OEM scan tool) is not capable of changing it once it's been set. As far as I know, only HP Tuners can change the VIN and other "non-changable" data, and it was about $700 when I bought it a year and a half ago. If this is a used one, you'll need to go to a shop that can program a new module. Some independant shops can do this, and will be a lot cheaper than the dealer. Have them install and program a new one. If you installed a new one, on some vehicles, once you try to start the engine, the data is locked in. Any mistakes are permanent and the module is nothing but a very expensive paperweight (unless you want to salvage the transistors and capacitors out of it, worthless unless one of your hobbies is playing around with electronics). Most of the new module programming I've done is on newer vehicles, and I'm not 100% sure that this applies to your vehicle, but it sure sounds like a module mismatch to me.

When I installed a used pcm in my car (gm intentionally destroys the original PCM when it's updated for the GMPP supercharger kit, it can never be programmed with anything again) I tried getting it to work using the Tech2, and it would not work until I reprogrammed it using HP Tuners.

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