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HOMESERVICE MANUALSCHEVROLET2003TRAILBLAZER 4.2 S, 4WDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 1755 (POWER DOOR LOCK SYSTEM AND RELEASE SYSTEMS)DIAGNOSTIC INFORMATION AND PROCEDURESPOWER DOOR LOCKS INOPERATIVECOMPONENT TESTING
2003 Chevrolet TrailBlazer 4.2 S, 4WD

Component Testing

2003 Chevrolet TrailBlazer 4.2 S, 4WDSECTION Component Testing
WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

Door Lock Switch Test

  1. Ignition OFF, disconnect the harness connector at the applicable door lock switch.
  2. Test for infinite resistance between the signal terminals B and C and the B+ terminal A with the switch in the open position.
    • If less than infinite resistance, replace the applicable door lock switch.
  3. Test for less than 2 ohms of resistance between the signal terminal B and the B+ terminal A with the switch in the lock position.
    • If greater than 2 ohms, replace the applicable door lock switch.
  4. Test for less than 2 ohms of resistance between the signal terminal C and the B+ terminal A with the switch in the unlock position.
    • If greater than 2 ohms, replace the applicable door lock switch.

Door Lock Actuator Test

  1. Install a 20A fused jumper wire between the control terminal 3 and 12 volts. Install a jumper wire between the ground terminal 2 and ground.
  2. Verify the actuator turns ON and OFF.
    • If the function does not perform as specified, replace the applicable door latch.

Relay Test

  1. Ignition OFF, disconnect the applicable relay.
  2. Test for 60-200 ohms of resistance between terminals 85 and 86.
    • If the resistance is not within the specified range, replace the relay.
  3. Test for infinite resistance between the following terminals:
    • 30 and 86
    • 30 and 87
    • 30 and 85
    • 85 and 87
    • If less than infinite resistance, replace the relay.
  4. Test for less than 2 ohms of resistance between terminals 30 and 87A.
    • If greater than 2 ohms, replace the relay.
  5. Install a 3-amp fused jumper wire between relay terminal 85 and 12 volts. Install a jumper wire between relay terminal 86 and ground. Measure for less than 2 ohms of resistance between terminals 30 and 87.
    • If greater than 2 ohms, replace the relay.
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