How To Replace GM Passlock Ignition Key Lock Cylinder and Relearn Procedure

NOTE: These instructions and pictures show how to replace the Ignition Lock Cylinder for the following vehicles:


2004 – 2005 Chevy Classic
2000 – 2005 Chevy Impala (Includes 04-05 Impala SS)
1997 – 2003 Chevy Malibu
2000 – 2005 Chevy Monte Carlo (Includes 04-05 Monte Carlo SS)
1999 – 2004 Oldsmobile Alero
1997 – 1999 Oldsmobile Cutlass
1998 – 2002 Oldsmobile Intrigue
1999 – 2005 Pontiac Grand Am


The ignition lock cylinder contains the pass-lock security chip that is extremely common to fail on the above vehicles. A typical symptom of failure is the security light illuminating on the dash. Also, keep in mind the electronic ignition switch is located just behind the lock cylinder. It is the plastic part that the ignition lock cylinder fits into. It contains the actual electrical connections and wiring and it sends current to numerous different components. This part is not as common as the lock cylinder, however many times it also needs replacement. A proper diagnosis is needed to verify these parts are failed or possibly failing intermittently.


APDTY 035813 Ignition Lock Cylinder Passlock Chip & Keys (Fixes Security Light)

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Removal and installation:

  1. Remove trim panel around radio, usually held in with snap-in clips, some vehicles may have a screw or two
  2. Unbolt and remove the radio to gain access to the back of the lock cylinder
  3. Press the small release tab (see pictures) While turning key to the ON Position
  4. Slide old lock cylinder out
  5. Installation is the reverse of the above procedures, see below for the relearn procedure


Pre-Relearn Procedure Check List

  1. Fully Charge Battery
  2. Clear all Diagnostic Trouble Codes (DTC). Record and/or repair your DTCs before clearing. You can clear the codes by disconnecting the battery for 10 minutes.

Relearn Procedure

  1. Turn ON the ignition, with the engine OFF
  2. Attempt to start the engine, then release the key to ON (vehicle will not start)
  3. Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF
  4. Turn OFF the ignition, and wait 5 seconds
  5. Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes (The vehicle is now ready to relearn the Passlock™ Sensor Data Code and/or passwords on the next ignition switch transition from OFF to CRANK)
    IMPORTANT The vehicle learns the Passlock™ Sensor Data Code and/or password on the next ignition switch transition from OFF to Crank. You must turn the ignition OFF before attempting to start the vehicle.
  6. Start the engine (the vehicle has now learned the Passlock™ Sensor Data Code and/or password)
  7. With a scan tool, clear any DTCs if needed (history DTCs will self-clear after 100 ignition cycles)
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