C1283

CIRCUIT DESCRIPTION
Steer angle centering is the process by which the Electronic Brake and Traction Control Module (EBTCM) calibrates the steering sensor output so that it reads zero when the steering wheel is centered. The initial steering wheel center position is calculated after driving 10 Km/h (6 mph) for more than 10 seconds in a straight line on a fairly level surface. The EBTCM uses the Yaw Rate Sensor, Lateral Accelerometer and Wheel Speed Sensors to tell if the vehicle is moving in a straight line. This centering routine is necessary to compensate for wear in the steering and suspension. Wear in the steering and suspension can result in a change in the relationship between the steering wheel and the front wheels. By running the centering routine the EBTCM can compensate for these changes by changing the digital and analog center position.

CONDITIONS FOR SETTING THE DTC
The initial steering wheel center position will be determined quickly unless there is a large offset in the yaw sensor or lateral accelerometer output. When this happens the system will believe the steering is far off center even though the vehicle is being driven in a straight line. Under this condition and with a continuous vehicle speed of 40 Km/h (25 mph) or greater for longer than 10 minutes, DTC C1283 will be set.

ACTION TAKEN WHEN THE DTC SETS
Antilock Brake System (ABS) and Traction Control System (TCS) remain enabled, Active Handling is disabled.
^ Indicators that turn on:
- Car Icon (TCS indicator)
^ Messages displayed on the Driver Information Center (DIC):
- Service Active HNDLG
- Service Vehicle Soon

CONDITIONS FOR CLEARING THE DTC
^ Condition for Diagnostic Trouble Code (DTC) is no longer present and Scan tool clear DTC function is used.
^ Fifty ignition cycles have passed with no DTCs detected.

DIAGNOSTIC AIDS
^ It is very important to check the vehicle for proper alignment. The car should not pull in either direction while driving straight on a flat surface.
^ It is very important to find out from the driver when the code was set (when the SERVICE ACTIVE HNDLG message was activated). This information may help to duplicate the failure.
^ It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
^ An intermittent malfunction is most likely caused by a poor connection, rubbed through wire insulation, or a wire that is broken inside the insulation. Refer to Testing for Electrical Intermittents in Diagnostic Aids.
^ The Snapshot function on the Scan tool may help in finding an intermittent Diagnostic Trouble Code (DTC) C1283.

TEST DESCRIPTION
The number(s) below refer to the step number(s) on the diagnostic table.
3. This step checks for the proper Lateral Accelerometer input.
5. This step checks for the proper Yaw Rate Sensor input.





DTC C1283 EXCESSIVE TIME TO CENTER STEERING