Chevy Impala Security System Problems

Introduced in 1958, the Chevrolet Impala is a full-size car manufactured by General Motors. The Chevrolet Impala can experience problems relating to its security system, called Passlock II, which often can be resolved through some troubleshooting steps.

Sensor Problems

  • The Chevrolet Impala security system relies on a sensor that detects the rotation of the lock cylinder, which can be performed successfully only by the proper key. The sensor can wear out over time and fail to submit a stable signal based on cylinder rotation, resulting in the inability to start the Impala. Replacing the sensor typically resolves the starting issue.

Lock Cylinder Problems

  • The lock cylinder in the Chevrolet Impala security system contains a key reader designed to detect the microchip encoded in the key. A worn or defective lock cylinder may fail to read the chip properly and signal the ECU that a non-encoded key has been used. The ECU then disables the engine to prevent theft. Replace the lock cylinder to restore proper security system function.

Security Light Flickers

  • If the security light for your Chevrolet Impala security system flickers on and off, a low-charge battery may be to blame. Check the battery for a secure connection as well as the terminals for corrosion before recharging it. If the battery is beyond its life expectancy or fails to recharge, replace it.