GM Service Manual Online
For 1990-2009 cars only

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Circuit/System Description

The inclination sensor detects changes in the parked angle of the vehicle. If a change greater than .3° 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.

Diagnostic Aids

The inclination sensor is a dealer installed accessory. Not all vehicles are equipped with an intrusion sensor. To determine if a particular vehicle is equipped with an inclination sensor, view the scan tool Cal. Part No. 2 parameter. This parameter can be found in the BCM Calibration ID menu.

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
    •  Scan Tool Data Definitions

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the inclination sensor.
  2. Ignition OFF, test for less than 1 ohm of resistance between the ground circuit terminal 4 and ground.
  3. If greater than the specified range, test the ground circuit for an open/high resistance.
  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.

    Important: Because of how the accessory inclination sensor is integrated into the vehicle, the inclination sensor uses the Hood Ajar Switch parameter to indicate its status. The Hood Ajar Switch parameter must be used when diagnosing the inclination sensor.

  6. Verify the scan tool Hood Ajar Switch parameter is Inactive.
  7. If not the specified value, test the signal circuit terminal 3 for a short to ground. If the circuit tests normal, replace the BCM.
  8. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the ground circuit terminal 4. Verify the scan tool Hood Ajar Switch Parameter is Active.
  9. If not the specified value, test the signal circuit for a short to voltage or and open/high resistance. If the circuit tests normal, replace the BCM.
  10. If all circuits test normal, test or replace the inclination sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, setup, and programming.