C1281

DTC C1281: Stabilitrak Sensors Uncorrelated (Part 1 Of 2):

DTC C1281: Stabilitrak Sensors Uncorrelated (Part 2 Of 2):

DTC C1281 Schematic:

CIRCUIT DESCRIPTION
Stabilitrak is activated by calculating the estimated yaw rate (based on wheel speed sensor inputs, lateral acceleration and steering wheel position formation) and comparing it to the actual yaw rate, measured by the yaw rate sensor. The difference between these two is the yaw rate error, which is a measurement of oversteer or understeer. If the yaw rate error becomes too large the system attempts to correct the vehicle's yaw motion by using differential braking on the left or right front wheel.

CONDITION FOR SETTING THE DTC
The output of analog and digital steering sensors do not agree for one second while in a Stabilitrak activation period. The estimated and actual yaw rates do not agree for 5 seconds while in a Stabilitrak activation period. DTC C1281 can be set any time after the steering angle has been centered and Stabilitrak is activated. If the estimated yaw rate and actual yaw rate do not match within 10 seconds, this code will be set. In most cases, one of these codes C1282, C1284-C1287 will set following code C1281. Normal conditions which could cause code C1281 to set include Stabilitrak~ activation's brought on by aggressive driving on extremely slippery road surfaces for example, spinning the car in one direction for greater than 10 seconds.

ACTION TAKEN WHEN THE DTC SETS
A malfunction DTC is stored, ABS and TCS remain enabled, Stabilitrak is disabled and the STABILITY REDUCED message will be displayed on the DIC.

CONDITIONS FOR CLEARING THE DTC
Condition for DTC is no longer present and scan tool clear DTC function is used. Fifty start cycles have passed with no DTCs detected.

DIAGNOSTIC AIDS
Check to ensure that the Yaw Rate Sensor is securely fastened to the package shelf. 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. It is very important to find out from the driver when the code was set, (i.e., when the STABILITY REDUCED message was activated). This information may be of help in duplicating the failure conditions. 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. The Snapshot function on the scan tool may help in finding an intermittent DTC C1281.

TEST DESCRIPTION
The numbers below refer to step numbers on the diagnostic table.
5. Check the Steering Wheel Position Sensor.
7. Checks the Yaw Rate Sensor.
9. Checks the EBTCM.