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Davo, Master technician
Category: Chevy
Satisfied Customers: 3253
Experience:  ASE Master Technician also L1 Advanced Engine Performance Specialist
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How to bypass security system on 1998 chevy pickup

Customer Question

I transfered 98 chevy cab onto a 98 GMC running gear. starts for 3 seconds then dies. security light stays on. let set for 10 minutes then shut key off then started. NO LUCK, didn't work. NO TROUBLE CODES FOUND, using OBD-II.
Submitted: 9 years ago.
Category: Chevy
Expert:  Davo replied 9 years ago.
Did you use the theft module and PCM from the donor cab?
Customer: replied 9 years ago.
My 98 GMC I started with is trashed but it was a base model. No extra's. No security system, vinel flooring, floor 4X4 shifter, ect. My chevy has electric 4X4, center overhead console. everything my otherone didn't. All I used that is different is the cab. 98 GMC motor, tranny, computer everything is gmc andI drove it to my buddies shop, transfered cab's and then it starts for 3 seconds then dies.
Expert:  Davo replied 9 years ago.
Disconnect the battery for 3 minutes and hold the cables together.Reconnect the battery and then do the following.
  • 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).
  • 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.
  • The SECURITY indicator will transition from flashing to ON briefly to OFF after 10 minutes if remaining in the ignition ON position.
  • Turn the ignition switch to the OFF position and wait for 10 seconds.
  • 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).
  • Customer: replied 9 years ago.
    So you have to disconnect the battery 3 times total?
    Expert:  Davo replied 9 years ago.

    No just do it once.


    Customer: replied 9 years ago.
    No luck still just starts for a second and the dies. I tried it about 3 times, all alittle different ways.