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Bob, Auto Service Technician
Category: Car
Satisfied Customers: 4087
Experience:  40 year GM Tech. +30 Certified. ASE Master Tech.(expired, retired) Medium Duty, Heavy Line, Retired
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1998 GMC: ext..cargo van..The trouble code P0560, P1361A and P1626C

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I have a 1998 GMC Savanna 2500 ext. cargo van. The trouble code P0560, P1361A and P1626C are coming up and the van won''t start. What do there codes mean and how do I fix them?

Hello, the P0560 is a problem with the charging system, alternator, battery or connections in the system. You will need to have the battery charged and then have the charging system testt. The 1626 and 1613 are related to the teft or security system and could very well be the reason it won't run. This system can only be tested with a class 2 scan tool like the dealers use. Here is some basic information on it.


You may experience a start/stall condition with a code P1626 or P1631 set in the PCM. An extended crank condition may cause a code P1626 or P1631 to set when there is no related theft deterrent codes.


To determine if a crank/no start or start/stall condition is being caused by a passlock theft deterrent concern, perform the following steps:

  1. Connect the Tech 2 to the vehicle, turn ignition to the on position.
  2. Select the "POWERTRAIN" option.
  3. Select "DATA DISPLAY".
  4. Select "ENGINE DATA 1" or "ENGINE DATA 2" and look for the "VTD FUEL DISABLE" parameter.
  5. Crank the engine. If the "VTD FUEL DISABLE" indicates "ACTIVE", the passlock theft deterrent system is disabling the fuel and you need to follow theft deterrent diagnosis. When the engine is cranked, if the "VTD FUEL DISABLE" indicates "INACTIVE", the no start condition is not being caused by a theft deterrent concern and normal no start diagnostics should be followed.
Customer: replied 9 years ago.
If the VTD indicates "Active", how do I fix it?

The system can only be tested with a class 2 scan tool like the dealers use. The most common things to go wrong with them are the ignition lock cylinder, and the two small wires inside the steering column that go to the module, tend to break from all of the flexing when the key is turned on and off. But that does not mean that it could not be something else. The big problem with this system is that there is no practical way to work around it or bypass it because part of it is an actual soft ware program that is loaded right into the computer and you would have to write all new software and reprogram the system to even get it to run with out it. You can try to re program the system and see if that will make it work. If not, your stuck until you can find a class 2 scan tool to check it with. A regular code reader won't even access the module for it. Class 2 is the only one that will work. Instructions for re program below. Do it step by step, no short cuts. Good luck.

  • (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 passlockTM sensor was replaced the SECURITY indicator will flash for the 10 minutes duration.
    - If the EVO/passlockTM 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 XXXXX XXXXX on the next ignition lock cylinder cycle from OFF to CRANK to ON (start attempt).

  • Document ID# XXXXX
    1998 GMC Truck Savana

    Customer: replied 9 years ago.
    Thanks Bob, I haven't had a chance to try it yet, but I hope to in the next few days and then will hit the pay button.

    Don't even worry about the button. Just let me know how it goes. More important that the truck works right than anything else. Just keep me informed. Thanks
    Bob and 5 other Car Specialists are ready to help you