Passlock™ Anti-Theft Auto Learn Method (Saturn - 1.9L)

2003 Chevrolet TrailBlazer 4.2 S, 4WDSECTION Passlock™ Anti-Theft Auto Learn Method (Saturn - 1.9L)
WARNING: This page does not describe the selected car, but rather 120 other vehicles, including the 2002 Saturn Vue, 2002 Saturn SL2, 2002 Saturn SL1, 2002 Saturn SL, and 2002 Saturn SC2. However, it is still accessible from the selected car via links, so may be relevant.
    NOTE: This method may be used if only the Passlock™ sensor was replaced. For PCM or BCM replacement, seed and key method must be used.
  1. Check BCM and PCM for existing codes. If codes exist, repair and proceed to next step. If no codes exist, go to next step.
  2. Turn ignition switch to RUN position. Momentarily rotate ignition switch to START position. DO NOT start vehicle. Wait for 10 minutes. When security light changes from flashing to off or on to off, turn ignition switch to OFF position. Perform this process 3 times. After the third time, vehicle should start on next ignition cycle.
    NOTE: If ignition is turned off before security light changes state, relearn procedure must be restarted.
RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.