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 Descriptor
DTC C0186
- Lateral Accelerometer Circuit


DTC C0196
- Yaw Rate Circuit




Circuit/System Description

The yaw rate, lateral and longitudinal accelerometers are combined into one combination sensor external to the electronic brake control module (EBCM). The combination sensor receives ignition power and a ground that is separate from the EBCM. The combination sensor sends dedicated serial data messages to the EBCM regarding vehicle yaw rate, lateral and longitudinal acceleration.


Conditions for Running the DTC

Ignition ON.


Conditions for Setting the DTC


C0186
* Lateral acceleration does not change when reducing speed from 30 km/h to 0 km/h and the condition occurs 16 times in a row
* Yaw rate, lateral and longitudinal acceleration do not correlate with the vehicle stationary
* Yaw rate, lateral and longitudinal acceleration do not correlate based on estimated wheel speed.
* Combination sensor fails an internal self test.
* Ignition voltage to the yaw/lateral combination sensor is less than 9.5 volts.
* Communication is lost between the EBCM and the combination sensor.



C0196
* Vehicle speed has reached at least 15 km/h (9 mph) from a stop more three times during the same ignition cycle. During the time the vehicle is stationary; the yaw rate signal value is more than 7 deg/sec for 2 seconds.
* When vehicle speed is more than 25 km/h (16 mph) in a turn the difference between the yaw rate, steering angle, lateral acceleration, and wheel speed sensor values are not correlated three consecutive times.
* Yaw rate changes greater than 20 deg/sec in 6 ms four times in one second.
* Combination sensor fails an internal self test.
* Ignition voltage to the combination sensor is less than 9.5 volts.
* Communication is lost between the EBCM and the combination sensor.



Action Taken When the DTC Sets


C0186
* The EBCM disables the Antilock Brake System (ABS)/Traction Control System (TCS)/Vehicle Stability Enhancement System (VSES) for the duration of the ignition cycle.
* A DIC message and/or a warning indicator may be displayed.



C0196
* The EBCM disables the VSES for the duration of the ignition cycle.
* A DIC message and/or a warning indicator may be displayed.



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 100 consecutive drive cycles.



Reference Information
Schematic Reference

Antilock Brake System Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Component Connector End 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 Testing

Note: It is recommend that the defective components be replaced, and not the complete brake master cylinder assembly.

1. Ignition OFF, disconnect the harness connector at the yaw rate/lateral and longitudinal accelerometer sensor.
2. Test for less than 1 ohm between the ground terminal 4 and ground.

• If greater than the specified range, test for an open/high resistance in the ground circuit.

3. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 1 and ground.

• If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the EBCM.

4. Ignition OFF, disconnect the X2 harness connector at the EBCM.
5. Ignition ON, test for less than 1 volt between the CAN HI circuit terminal 11 and ground.

• If greater than the specified value, test the CAN HI circuit for a short to voltage.

6. Test for less than 1 volt between the CAN LO circuit terminal 25 and ground.

• If greater than the specified value, test the CAN LO circuit for a short to voltage.

7. Ignition OFF, test for infinite resistance between the CAN HI circuit terminal 11 and ground.

• If not the specified value, test the suspect circuit for a short to ground.

8. Ignition OFF, test for infinite resistance between the CAN LO circuit terminal 25 and ground.

• If not the specified value, test the CAN LO circuit for a short to ground.

9. Test for less than 1 ohm between the CAN HI circuit terminal 11 and terminal 2.

• If greater than the specified range, test the CAN HI circuit for an open/high resistance.

10. Test for less than 1 ohm between the CAN LO circuit terminal 3 and terminal 25.

• If greater than the specified range, test the CAN LO circuit for an open/high resistance.

11. If all circuits test normal, replace the Yaw Rate/Lateral sensor.



Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.


Vehicle Yaw Sensor with Vehicle Lateral and Longitudinal Accelerometer Replacement (Service and Repair)