C0186

DTC C0186

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 0A
- Lateral Accelerometer Circuit Rate of Change Below Threshold

DTC C0186 5A
- Lateral Accelerometer Circuit Plausibility Failure

DTC C0186 71
- Lateral Accelerometer Circuit Invalid Serial Data Received

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.

Conditions for Running the DTC

The ignition switch is in the ON position.

Conditions for Setting the DTC

* The yaw/lateral combination sensor fails an internal self test.
* Communication is lost between the EBCM and the yaw/lateral combination sensor.

Action Taken When the DTC Sets

One or more of the following actions may occur:

* The vehicle stability enhancement system (VSES) is disabled.
* Traction control system (TCS) is disabled.
* A DIC message and/or a warning message may be displayed.

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.

Reference Information
Schematic Reference

Antilock Brake System Schematics (Electrical Diagrams)
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

1. Ignition ON, observe the scan tool Lateral Accelerometer Signal parameter. The reading should be 2.5 volts.
2. Ignition ON, observe the scan tool Yaw Rate Sensor parameter. The reading should be 2.5 volts.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the yaw rate/lateral accelerometer.
2. Test for less than 25 ohms between the ground circuit terminal 6 and ground.

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

3. Ignition ON, test for 11.8-12.2 volts between the 12-volt reference circuit terminal 1 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 yaw rate/lateral accelerometer sensor.

4. Test for 2.2-2.8 volts between the CAN circuit terminal 4 and ground.

• If greater than the specified range, test the CAN circuit for a short to voltage. If the circuit tests normal, replace the yaw rate/lateral accelerometer sensor.

• If less than the specified range, test the CAN circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the yaw rate/lateral accelerometer sensor.

5. Test for 2.2-2.8 volts between the CAN circuit terminal 5 and ground.

• If greater than the specified range, test the CAN circuit for a short to voltage. If the circuit tests normal, replace the yaw rate/lateral accelerometer sensor.

• If less than the specified range, test the CAN circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the yaw rate/lateral accelerometer sensor.

6. Test for infinite ohm between the CAN circuit High, and Low terminals 4 and 5.

• If less than the specified range, test the CAN circuits for a shorted to each other. If the circuit tests normal, replace the EBCM.

7. If all circuits test normal, test or replace the EBCM.

Repair Instructions

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

Control Module References (Programming and Relearning) for EBCM replacement, setup and programming