C0186
DTC C0186 or C0196
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions)provides an overview of each diagnostic category.
DTC Descriptors
DTC C0186 00
- Lateral Accelerometer Circuit
DTC C0186 5A
- Lateral Accelerometer Circuit Plausibility Failure
DTC C0196 00
- Yaw Rate Circuit
DTC C0196 5A
- Yaw Rate Circuit Plausibility Failure
Diagnostic Fault Information
Circuit/System Description
The electronic brake control module (EBCM) supplies ignition voltage and a low reference to the steering wheel speed position sensor and the yaw/lateral accelerometer sensor.
The yaw rate and the lateral accelerometer sensors are combined into one sensor, external to the electronic brake control module (EBCM). The vehicle stability enhancement system (VSES) uses the lateral accelerometer input when calculating the desired yaw rate. The yaw/lateral accelerometer sensor communicates with the EBCM via discrete CAN Bus High and CAN Bus Low serial data circuits.
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
* Short to ground on the CAN High serial data circuit.
* The yaw/lateral accelerometer sensor fails an internal self test.
* Communication is lost between the EBCM and the yaw/lateral accelerometer sensor.
* The correlation error between the yaw/lateral accelerometer sensor and the steering wheel speed position sensor.
Action Taken When the DTC Sets
One or more of the following actions may occur:
* The EBCM disables the antilock brake system (ABS)/traction control system (TCS) and vehicle stability enhancement system (VSES) for the duration of the ignition cycle.
* The ABS indicator illuminates.
* The Stabilitrak indicator illuminates.
* The driver information center displays All Wheel Drive Off/ Service Traction Control / Service Stabilitrak message.
Conditions for Clearing the DTC
* The condition for the DTC is no longer present.
* The EBCM clears the history DTC when a current DTC is not detected in 40 consecutive drive cycles.
Note: During normal diagnostic and/or repair verification technicians may find that the ABS, Traction Control and/or Stabilitrak indicators may be ON with NO DTCs displayed by the EBCM. Do not replace the EBCM for this condition.
If the ABS, Traction Control and/or Stabilitrak telltales are ON with no DTCs set, perform the following steps:
1. Remove the key from the ignition, open and close the driver's door to turn off retained accessory power (RAP), and wait 60 seconds.
2. Ignition ON, if the ABS, Traction Control and/or Stabilitrak telltales are still illuminated, operate the vehicle at speeds greater than 15 km/h (10 mph) to complete the self test. The EBCM should request all telltale indicators to turn OFF.
3. If the telltales remain ON with no DTCs set after the drive cycle, disconnect the battery for at least 60 seconds then reconnect the battery.
4. Operate the vehicle at speeds greater than 40 km/h (25 mph), the EBCM should request all telltale indicators to turn OFF.
Diagnostic Aids
* Inspect the steering column wiring harness for chafing, when the steering wheel telescoping feature is adjusted all the way in and the tilt is cycled up or down.
* Verify the yaw/lateral accelerometer sensor is installed correctly.
Reference Information
Schematic Reference
Antilock Brake System Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Description and Operation
ABS Description and Operation (Description and Operation)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing For Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
Scan Tool Reference
Control Module References (Programming and Relearning)for scan tool information
Circuit/System Testing
Note: Inspect the complete steering column wiring harness for chafing as the harness routes along and below the steering column. The wires in the steering column harness may be chafed or cut on the tilt telescope mechanism edges.
1. Verify that DTC C0710 is not set.
• If the DTC is set, refer to DTC C0710 (C0710).
2. Ignition OFF, disconnect the harness connector at the yaw/lateral accelerometer sensor.
3. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 10 ohm between the low reference circuit terminal 1 and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance.
4. Ignition ON, test for B+ between the ignition voltage circuit terminal 4 and ground.
• If not within the specified range, test the ignition voltage circuit for a short to ground or open/high resistance.
5. If all circuits test normal, replace the yaw/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)