1998 PCM Swap

V_Kint said:

I....1998 Suburban....My question - will the truck run with a stock PCM that hasn't been programmed with the VIN?....

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PASSLOCK REPROGRAMMING AUTO LEARN

IMPORTANT: If a new vehicle/powertrain control module (VCM/PCM) is being installed for the first the manufacturing enable bit will be set and the auto learn procedure may not be necessary.

The following procedure allows for anyone to reprogram the EVO/PASSLOCK module learned data code with any tools, other than the scan tool, when any of the following parts are replaced:

The EVO/PASSLOCK module
The PASSLOCK sensor
The VCM/PCM

The EVO/PASSLOCK module will set the DTC B3031 in the learn mode when entering the reprogramming procedure.

IMPORTANT: Erase the PASSLOCK related Diagnostic Trouble Codes (DTCs) that are stored in the VCM/PCM.

The following is the Auto Learn Procedure:

1. Insure the ignition key is in the ON position.
2. Clear all EVO/PASSLOCK module and VCM/PCM DTCs.
3. Momentarily rotate the ignition key to the CRANK position (Do NOT start the vehicle), then release it to the RUN position (Do NOT key OFF in the process).
4. Wait 10 minutes . Observe the SECURITY indicator. Refer to the following list for the appropriate responses:

-If the PASSLOCK sensor was replaced the SECURITY indicator will flash for the 10 minutes duration.
-If the EVO/PASSLOCK module was replaced, the SECURITY indicator will flash for a few seconds and then remain ON for the remainder of the 10 minutes duration.
-If the VCM/PCM was replaced with a new programmed VCM/PCM and connected to the vehicle for the first time, the vehicle will start and this procedure may not be necessary.
-If the replacement VCM/PCM was connected to any vehicle at any other time, even momentarily, the SECURITY indicator will flash for a few seconds and then remain ON for the 10 minutes duration.

5. The SECURITY indicator will transition from flashing to ON briefly to OFF after 10 minutes if remaining in the ignition ON position.
6. Turn the ignition switch to the OFF position and wait for 10 seconds .
7. Repeat steps 3-6 two more times. The new security code is ready to be communicated among the PASSLOCK sensor, EVO/PASSLOCK module and VCM/PCM. The new password is learned on the next ignition lock cylinder cycle from OFF to CRANK to ON (start attempt).

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V_Kint said:

Thanks to everyone for the input - good info. I tried replacing mine with a unit from a 99 with the same equipment, but as @mattillac mentioned it would only run for a a second or two before dying. I need to see if I can find someone local to program it and give it another shot.

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Mrich0908 said:

Ya that would be your vats huh .
This document below may help may not. I also did a crank relearn procedure before I tried starting it. Its similar to this but little different .
GM Document ID 835015 helps you with this one.

You must perform a theft relearn procedure if any of the following components have been changed.

PASSLOCK TM

BODY CONTROL MODULE

POWERTRAIN CONTROL MODULE

The above modules, with the exception for the PASSLOCK Sensor must also be programmed with each module's own vehicle configuration. See the individual module service manual section.

Auto Learn:

Time required, approximately 10 minutes

1. Insure that the battery is fully charged.
2. Use the scan tool in order to clear the DTCs. ( Now, I did not do this because I was using the same key but a different ignition cylinder) The dealer set up the new ignition cylinder to accept our key tumblers inside the unit. It took them a few minutes to do this but the ignition cylinder kit came with instructions on how to do this yourself but it was nice of the dealer to set it up. (another reason I used the dealer to purchase the parts)
3. Turn the ignition switch from the OFF position to the CRANK position attempting to start the vehicle. The vehicle will start and then stall. (do not try to restart, just let go of the key so it stays in the ON position by itself) Do not turn it back to off or you will have to repeat step 3 again.
4. Leave the ignition switch in the ON position while observing the security indicator.
5. When the security indicator on the instrument panel shuts off, which can take up to 10 minutes (it took ours 15 minutes), turn the ignition switch off. Wait 10 second and try to start the car. It should stay running now.

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