C1282

DTC C1282

Circuit Description
The Vehicle Stability Enhancement System (VSES) is activated by the Electronic Brake Control Module (EBCM) calculating the desired yaw rate and comparing it to the actual yaw rate input. The desired yaw rate is calculated from measured steering wheel position, vehicle speed, and lateral acceleration. The difference between the desired yaw rate and actual yaw rate is the yaw rate error, which is a measurement of oversteer or understeer. If the yaw rate error becomes too large, the EBCM will attempt to correct the vehicle's yaw motion by applying differential braking to the left or right front wheel.

DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC C1282 Yaw Rate Sensor Bias Circuit Malfunction

Conditions for Running the DTC
The EBCM performs 6 different tests to detect a DTC condition. The numbers below correspond to the numbers in Conditions for Setting the DTC.
1. The yaw rate sensor bias test runs with the ignition ON.
2. The yaw rate sensor acceleration test runs with the ignition ON.
3. The yaw rate sensor circuit test runs with the vehicle stopped or with the vehicle speed greater than 45 km/h (28 mph).
4. The yaw rate isolation test runs with the following conditions:
^ The brake pedal is not pressed.
^ The Antilock Brake System (ABS) is not active.
^ The vehicle speed is greater than 5 km/h (3 mph).

5. The above yaw rate isolation test runs with the VSES active.
6. The false activation test runs with the VSES active.

Conditions for Setting the DTC
The EBCM performs 6 different tests to detect a DTC condition. The numbers below correspond to the numbers in Conditions for Running the DTC.
1. The yaw rate bias is greater than 7 degrees/second.
2. The yaw rate input change is greater than 390 degrees/second/second.
3. The yaw rate input voltage is less than 0.15 volts or greater than 4.85 volts for one second.
4. The yaw rate error is greater than 10 degrees/second 30 times within a drive cycle.
5. The yaw rate error is greater than 10 degrees/second for 5 seconds. Under this condition, this DTC will set along with DTC C1281.
6. The yaw rate error is greater than 10 degrees/second with the vehicle speed less than 60 km/h (37 mph), and the acceleration pedal is pressed more than 25 percent of the pedal travel range for one second during the VSES activation. Under this condition, this DTC will set along with DTC C1281.

Action Taken When the DTC Sets
^ The EBCM disables the VSES for the duration of the ignition cycle.
^ The Driver Information Center (DIC) displays the Service Stability System message.
^ The ABS/Traction Control System (TCS) remains functional.

Conditions for Clearing the DTC
^ The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
^ The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Diagnostic Aids
The following conditions can cause this concern:
^ Improper steering alignment
^ Open, short to ground, or short to voltage
^ Internal lateral accelerometer failure
^ EBCM internal failure

Test Description
The numbers below refer to the step numbers on the diagnostic table.
3. This step tests for the proper operation of the circuit in the low voltage range.
4. This step tests for the proper operation of the 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.
5. This step tests for a short to voltage in the 5-volt reference circuit.
6. This step tests the bias voltage of the yaw rate sensor.











DTC C1282