98 5.0 TO 5.7 SWAP pcm problems

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silverado98

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Well guys i finally finished the swap on my 98 c1500 5.0 to 5.7 but im having an issue with it. When bought the 5.7 vortec i also got the pcm that goes with that motor as well but when i took the 5.0 pcm and put the 5.7 pcm in after the swap it did crank but did not turn over. So what i did was put the 5.0 pcm back in it and it fired right up but I know it will run like **** with that pcm cause its for 5.0 vortec. I think it has something to do with the security light cause when the 5.7 pcm is in will flash then stay solid but it will crank just wont turn over and if the 5.0 pcm is on then it will flash then go away and it will crank and turn over and run.
Has anyone have this problem before please help if so.
 

mattillac

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Sounds normal, here is the procedure for programming the 5.7 PCM to your trucks existing module and sensor..


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).



Should take a bit more than 30 minutes.

Step #2 is not necessary.

Step #3 can be a bit tricky, ("do not start" even though the key needs to be rotated to the start / crank position), it's okay if the engine starts and stalls (if that happens all is not lost), the important thing to do is leave the key in the run postition for the ten minute durations.

If i you ever have any custom tuning done to the PCM, the passlock feature can be (eliminated) tuned out.

Best of luck.
 
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