GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2008 🢒 STS 🢒 Driver Information and Entertainment 🢒 Cellular, Entertainment, and Navigation 🢒 DTC C0287

Circuit Description

The longitudinal sensor is part of the yaw/lateral sensor assembly. The longitudinal sensor only used on 4-wheel drive (4WD) vehicles. The longitudinal accelerometer is communicated on the chassis CAN at a regular interval.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0287 09 Longitudinal Accelerometer Circuit Rate of Change Above Threshold

DTC C0287 1A Longitudinal Accelerometer Circuit Bias out of Range

DTC C0287 75 Longitudinal Accelerometer Circuit Signal Above Allowable Range

Conditions for Running the DTC
    • The ignition is ON.
    • The vehicle stability enhancement system (VSES) sensors have been successfully initialized.
    • The DTC C0561 71 is not set as a result of a longitudinal acceleration sensor circuit or internal fault during the current ignition cycle

Conditions for Setting the DTC

Any of the following conditions may cause the DTC to set:

    • An erratic longitudinal accelerometer signal is detected.
    • The stability control system detects that the longitudinal accelerometer sensor signal does not correspond with signals from other sensors.

Action Taken When the DTC Sets
    • The stability control system disables the VSES.
    • The service stability message is displayed.

Conditions for Clearing the DTC
    • The condition for setting the DTC is no longer present.
    • The EBCM automatically clears a history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Diagnostic Aids
    • Check the vehicle for proper steering alignment.
    • The Snapshot function on the scan tool can help find an intermittent DTC.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

ABS Description and Operation

Electrical Information Reference

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

Scan Tool Reference

Control Module References for Scan Tool Information

Circuit/System Verification

Ignition ON, observe the scan tool yaw rate and lateral accelerometer sensor parameter. The reading should be the same on all sensors when driving in a straight line at a constant speed greater than 20 km/h (13 mph), and will vary as the vehicle changes direction.

Circuit/System Testing
  1. Ignition OFF, disconnect the harness connector at the Yaw Rate/Lateral Accelerometer sensor.
  2. Test for less than 1 ohm of resistance between the ground circuit terminal 1 and ground.
    3. ⇒If greater than the specified range, test for an open/high resistance in the ground circuit.
  3. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 4 and ground.
    4. ⇒ If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
  4. Ignition OFF, disconnect the harness connector X3 at the Vehicle Stability Control Module (VSCM).
  5. Ignition ON, test for 0 volts between the communication circuit terminal 52 and ground.
    6. ⇒If greater than the specified value, test the communication circuit for a short to voltage.
  6. Test for 0 volts between the communication circuit terminal 72 and ground.
    7. ⇒If greater than the specified value, test the communication circuit for a short to voltage.
  7. Ignition OFF, test for infinite resistance between the communication circuit terminal 52 and ground.
    8. ⇒If not the specified value, test the communication circuit for a short to ground.
  8. Test for infinite resistance between the communication circuit terminal 72 and ground.
    9. ⇒If not the specified value, test the communication circuit for a short to ground.
  9. Test for less than 1 ohm of resistance between the communication circuit terminals 72 and terminal 3.
    10. ⇒If greater than the specified range, test the communication circuit for an open/high resistance.
  10. Test for less than 1 ohm of resistance between the communication circuit terminals 52 and terminal 2.
    11. ⇒If greater than the specified range, test the communication circuit for an open/high resistance.
  11. Test for infinite resistance between the communication circuit 52 and the communication circuit 72.
    12. ⇒If not the specified value, test the communication circuits for a short together.
  12. If all circuits test normal, replace the Yaw Rate/Lateral sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Vehicle Yaw Sensor with Vehicle Lateral Accelerometer Replacement
    •  Vehicle Yaw Sensor with Vehicle Lateral and Longitudinal Accelerometer Replacement
    •  Control Module References for EBCM replacement, setup, and programming