C0186

DTC C0186

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 Descriptors
DTC C0186 00
- Lateral Accelerometer Circuit Electrical Failure

DTC C0186 5A
- Lateral Accelerometer Circuit Erratic

DTC C0186 3B
- Lateral Accelerometer Self Test Failure

DTC C0186 1A
- Lateral Accelerometer Offset Failure




Diagnostic Fault Information






Circuit/System Description

The lateral accelerometer and the yaw rate 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 usable output signal is a serial data CAN circuits.


Conditions for Running the DTC

The ignition switch is in the ON position.


Conditions for Setting the DTC

* The yaw/lateral combination sensor reports an internal failure.
* The yaw/lateral combination sensor learns a wrong offset value.
* Incorrectly mounted yaw/lateral sensor.



Action Taken When the DTC Sets

One or more of the following actions may occur:

* Vehicle stability enhancement system (VSES) are disabled.
* The VSES indicator turns ON.
* The driver information center (DIC) displays the Service ESC message.



Conditions for Clearing the DTC

* The condition for the DTC is no longer present.
* The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.



Diagnostic Aids

Possible causes of this DTC are as follows:

* Incorrectly mounted yaw/lateral sensor
* Internal failure in the yaw/lateral sensor
* Intermittent wiring connections



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)
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 EBCM


Circuit/System Verification

With scan tool installed, clear the DTCs then drive the vehicle in a straight line at a speed greater than 20 km/h (13 mph). If the DTC did not set as a current DTC see Diagnostic Aids.


Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the yaw rate/lateral accelerometer .
2. Test for less than 6 ohm of resistance between the low reference circuit terminal 6 and ground.

• If greater than the specified range, test for an open/high resistance in the low reference circuit. If the circuit tests normal, replace the EBCM.

3. Ignition ON, test for 11.8-12.2 volts between the 12-volt reference circuit terminal 3 and ground.

• If less than the specified range, test the 12-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the EBCM.


• If greater than the specified range, test the 12-volt reference circuit for a short to voltage. If the circuit tests normal, replace the EBCM.

4. Ignition OFF, disconnect the harness connector at the steering angle sensor.
5. Ignition ON, test for 0 volts between the communication circuit terminal 5 and ground.

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

6. Test for 0 volts between the communication circuit terminal 2 and ground.

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

7. Ignition OFF, test for infinite resistance between the communication circuit terminal 5 and ground.

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

8. Test for infinite resistance between the communication circuit terminal 2 and ground.

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

9. Test for less than 1 ohm of resistance between the yaw rate sensor circuit terminals 1 and steering wheel sensor terminal 5.

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

10. Test for less than 1 ohm of resistance between the yaw rate sensor circuit terminal 2 and steering wheel sensor terminal 2.

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

11. Test for infinite resistance between the communication circuit 5 and the communication circuit 2.

• If not the specified value, test the communication circuits for a short together.

12. 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.

* Steering Angle Sensor Centering (Procedures)
* Diagnostic Test Drive (Diagnostic Test Drive)
* Control Module References (Programming and Relearning) for EBCM replacement, setup, and programming