GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description

The inclination sensor detects changes in the parked angle of the vehicle. If a change greater than 3 degrees for a 7 second period is detected, the vehicles content theft alarm is sounded. The sensor recalibrates itself each time the vehicle is parked, which allows it to account for parking on steep grades without unintentional activation.

Reference Information

Schematic Reference

Theft Deterrent System Schematics

Connector End View Reference

Theft Deterrent System Connector End Views

Description and Operation

Content Theft Deterrent (CTD) Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Scan Tool Data List

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the inclination sensor.
  2. Ignition OFF, test for less than 1.0 ohm of resistance between the low reference circuit terminal 4 and ground.
  3. If greater than the specified range, test the low reference circuit for an open/high resistance. If circuit tests normal, replace the BCM.
  4. Ignition ON, verify a test lamp illuminates between the B+ circuit terminal 1 and ground.
  5. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  6. Verify the scan tool Inclination Sensor parameter is Inactive.
  7. If not the specified range, test the signal circuit terminal 3 for a short to ground or an open/high resistance. If the circuit tests normal, replace the XBCM.
  8. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the low reference circuit terminal 4. Verify the scan tool Inclination Sensor Parameter is Active.
  9. If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the XBCM.
  10. If all circuits test normal, replace the inclination sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Refer to Control Module References for BCM and XBCM replacement, setup, and programming.