C1288

Circuit Description
The steering wheel position sensor supplies 2 analog inputs, Phase A and Phase B, to the EBCM. The 2 input signals are approximately 90° out of phase. By interpreting the relationship between the 2 inputs, the EBCM can determine the position of the steering wheel and the direction of steering wheel rotation.
Steer angle centering is the process by which the EBCM calibrates the steering sensor output so that the output reads zero when the steering wheel is centered. Using the yaw rate input, lateral accelerometer input, and wheel speed sensor inputs, the initial steering center position is calculated after driving greater than 10 km/h (6 mph) for more than 10 seconds in a straight line on a level surface.

Conditions for Running the DTC
The ignition is ON.

Conditions for Setting the DTC
One of the following conditions occur:
^ Phase A and Phase B are greater than 4.9 volts for 1.6 second.
^ Phase A and Phase B are less than 0.2 volts for 1.6 second.

Action Taken When the DTC Sets
^ The EBCM disables the VSES for the duration of the ignition cycle.
^ The DIC displays the SERVICE STABILITY SYSTEM message.
^ The ABS/TCS remains functional.

Conditions for Clearing the DTC
^ The condition for the DTC is no longer present (the DTC is not current) and you used the scan tool Clear DTC function.
^ The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Diagnostic Aids
^ During diagnosis, park the vehicle on a level surface.
^ Check the vehicle for proper alignment. The car should not pull in either direction while driving straight on a level surface.
^ Find out from the driver under what conditions the DTC was set (when the DIC displayed the SERVICE STABILITY SYSTEM message). This information will help to duplicate the failure.
^ The Snapshot function on the scan tool can help find an intermittent DTC.

Test Description
The number below refers to the step number on the diagnostic table.
2. This step performs the Steering Position Sensor Test to see if the Steering Wheel Position Sensor (SWPS) is operating properly.
3. Tests for the proper operation of the Phase A circuit in the low voltage range.
4. Tests for the proper operation of the Phase B circuit in the low voltage range.
5. Tests for the proper operation of the Phase A circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to ground.
6. Tests for the proper operation of the Phase B circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to ground.
7. Tests for a short to voltage in the 5 volt reference circuit.
8. Tests for a high resistance or an open in the ground circuit.