C0287

DTC C0287

Circuit Description
The electronic brake control module (EBCM) provides power 5-volt reference to the longitudinal accelerometer. The longitudinal accelerometer converts the change in vehicle motion, or inertia, into a voltage signal. This signal is sent to the EBCM.

The voltage signal ranges, from 2.4-2.6 volts at zero speed change, constant motion, or stationary. The longitudinal accelerometer voltage signal drops when the vehicle is under acceleration. The longitudinal accelerometer voltage signal increases when the vehicle is under deceleration. The usable output voltage range for the longitudinal accelerometer is 0.48 - 4.82 volts. The longitudinal accelerometer sensor bias compensates for sensor mounting alignment errors and electronic signal errors.

DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC C0287 Longitudnal Accelerometer Circuit

Conditions for Running the DTC
^ The ignition is ON.
^ The vehicle stability enhancement system (VSES) sensors have been successfully initialized or the message center has displayed the stability system disabled message due to an unsuccessful initialization attempt. Refer to ABS Description and Operation for a complete explanation of VSES sensor initialization.
^ The vehicle is being driven relatively straight and level at a speed greater than 11 km/h (7 mph), before performing a stable turning maneuver.

Conditions for Setting the DTC
Any of the following conditions may cause the DTC to set:
^ Open Longitudnal accelerometer circuitry is detected.
^ Shorted Longitudnal accelerometer circuitry is detected.
^ An erratic Longitudnal accelerometer signal is detected.
^ The EBCM detects that the Longitudnal accelerometer sensor signal does not correspond with signals from other sensors.

Action Taken When the DTC Sets
^ The EBCM disables the VSES.
^ The stability indicator turns ON.

Conditions for Clearing the DTC
The conditions for setting the DTC are no longer present and you use the scan tool Clear DTC's function.

Diagnostic Aids
^ Inspect the vehicle for proper wheel alignment. Ensure the vehicle does not pull toward the left or right while driving straight forward on a level surface.
^ Communicate with the customer to determine the conditions under which the message center displays the Service Stability System message. Learning the conditions under which the DTC sets may help you duplicate the failure.
^ Use the Snapshot function on the scan tool in order to assist you in locating an intermittent malfunction.

Test Description

Step 1 - Step 5:

Step 6 - Step 10:

The numbers below refer to the step numbers on the diagnostic table.
3. This step tests the sensor circuitry in the high voltage range.
4. This step tests the sensor circuitry in the low voltage range.