C0197

Circuit Description
The EBCM triggers a yaw rate sensor test every 40 milliseconds and switches the sensor into test mode. The EBCM sends a test signal to the sensor via the test circuit. When the test is run, the measured yaw rate from the sensor to the EBCM must be in the range of 25° per second ± 7° per second. At standstill, the vehicle yaw rate is zero. The yaw rate signal at standstill is called the offset. If calibration at standstill is not possible, a quick calibration during driving is done. The measured yaw rate is calibrated to a calculated reference yaw rate signal. Yaw rate sensor sensitivity is estimated by comparison of the reference yaw rate and the measured yaw rate during cornering.
Steering 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. The PCS steering angle sensor centering process is performed manually.

Conditions for Running the DTC
^ The ignition is ON.
^ The vehicle speed is greater than 40 km/h (25 mph).

Conditions for Setting the DTC
A malfunction is detected if one or more of the following conditions exist:
^ The yaw rate sensor signal is out of range for 220 - 420 milliseconds.
^ The yaw rate sensor signal at standstill which is called the offset is outside the allowed range of ± 8° per second.
^ The sensor sensitivity which is estimated by comparing the reference yaw rate and the measured yaw rate during cornering, is outside a predetermined range.
^ The yaw rate is changing at a rate greater than 6 - 23° per second per 40 milliseconds.

Action Taken When the DTC Sets
^ A malfunction DTC is set
^ TCS and VSES are disabled TCS, SERVICE VEHICLE SOON and PCS lamp indicators turn on

Conditions for Clearing the DTC
^ The condition for the DTC is no longer present
^ A history DTC will clear after 124 consecutive ignition cycles if the condition for the malfunction is no longer present.
^ Using a scan tool.

Diagnostic Aids
The following conditions may cause a malfunction:
^ Malfunctioning lateral accelerometer
^ Malfunctioning EBCM

Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
2. Checks to see if steering angle sensor is centered.
3. Checks for specified voltage on the lateral accelerometer signal circuit.
4. Checks for specified voltage on the yaw rate signal circuit.