C0197
DTC C0197
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
DTC Descriptor
DTC C0197 00
- Yaw Rate Circuit Range Performance
Diagnostic Fault Information
Circuit Description
The electronic brake control module (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 degrees per second that is greater or less then 7 degrees 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 vehicle stability enhancement system (VSES) steering angle sensor centering process is performed manually.
Conditions for Running the DTC
* Ignition 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 that is greater or less then 8 degrees 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 degrees per second per 40 milliseconds.
Action Taken When the DTC Sets
If equipped, the following actions occur:
* The EBCM disables the traction control system (TCS)/VSES for the duration of the ignition cycle.
* The antilock brake system (ABS) indicator illuminates.
* The Stability Off indicator illuminates.
Conditions for Clearing the DTC
* The condition for the DTC is no longer present.
* A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
Diagnostic Aids
Important: Perform the steering angle sensor centering procedure after the diagnostic system check-vehicle is performed. Refer to Steering Angle Sensor Centering (Procedures).
The following conditions may cause a malfunction:
* Malfunctioning lateral accelerometer
* Malfunctioning EBCM
Reference Information
Schematic Reference
Antilock Brake System Schematics ([1][2]Antilock Brakes / Traction Control Systems)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
ABS Description and Operation (Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning) for Scan Tool Information
Circuit/System Verification
Drive vehicle above 40 km/h (25 mph), verify the scan tool Yaw Rate Sensor °/sec value in the scan tool VSES scan tool data. The specified value should change the display at a rate greater than 6-23 degrees per second per 40 milliseconds.
Circuit/System Testing
1. Ignition OFF, disconnect the EBCM harness connector at the Yaw and Lateral Accelerometer Sensor.
2. Ignition OFF, with a DMM test for less than 5.0 ohms of resistance between the Vehicle Yaw and Lateral Accelerometer Sensor ground circuit terminal 6 and ground.
• If greater than the specified range, with the DMM test the low reference circuit terminal 6 for an open/high resistance. If the circuit tests normal, replace the EBCM.
3. Ignition ON, with a DMM test for 2.3-2.7 volts between the Yaw and Lateral Accelerometer Sensor lateral accelerometer signal circuit terminal 5 and ground.
• If less than the specified range, with the DMM test the lateral accelerometer signal circuit terminal 5 for a short to ground or an open/high resistance. If the circuit tests normal, replace the EBCM.
• If greater than the specified range, with the DMM test the lateral accelerometer signal circuit terminal 5 for a short to voltage. If the circuit tests normal, replace the EBCM.
4. Ignition ON, with a DMM test for 2.3-2.7 volts between the Yaw and Lateral Accelerometer Sensor yaw rate signal circuit terminal 4 and ground.
• If less than the specified range, with the DMM test the yaw rate signal circuit terminal 4 for a short to ground or an open/high resistance. If the circuit tests normal, replace the EBCM.
• If greater than the specified range, with the DMM test the yaw rate signal circuit terminal 4 for a short to voltage. If the circuit tests normal, replace the EBCM.
5. If all circuits test normal, test or replace the Yaw and Lateral Accelerometer Sensor.
Component Testing
1. Install a 3A fused jumper wire between the Yaw and Lateral Accelerometer Sensor yaw rate sensor signal terminal 4 and 5 volts. Install a jumper wire between the ground circuit terminal 6 and ground.
2. Sweep the sensor through the entire range while monitoring the resistance between the signal circuit terminal 5 and the low reference circuit terminal 6. The voltage should vary between 2.3-2.7 volts without any spikes or dropouts.
• If not within the specified range or is erratic, replace the Yaw and Lateral Accelerometer Sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Vehicle Yaw Sensor with Vehicle Lateral Accelerometer Replacement (Service and Repair)
* Steering Wheel Position Sensor or Steering Shaft Lower Bearing Replacement (Steering Wheel Position Sensor or Steering Shaft Lower Bearing Replacement)
* Control Module References (Programming and Relearning) for EBCM replacement, setup, and programming