C0186

DTC C0186

DTC Descriptors

DTC C0186 00

Lateral Accelerometer Circuit

DTC C0186 5A

Lateral Accelerometer Circuit Erratic

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview





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 signal controller area network (CAN) high and CAN low serial data circuits.

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.
^ The TCS/VSES indicators turn ON.
^ The driver information center (DIC) displays the Service Traction Control, and or Service Stabilitrak 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:

CAN HI and CAN LO circuits shorted together

CAN HI or CAN LO circuit shorted to ground

CAN HI or CAN LO circuit shorted to voltage

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Antilock Brake System Connector End Views

Description and Operation

ABS Description and Operation (Under 8600 GVW ) ABS Description and Operation (Equal to or Over 8600 GVW)

Electrical Information Reference
^ Circuit Testing
^ Connector Repairs
^ Testing for Intermittent Conditions and Poor Connections
^ Wiring Repairs

Scan Tool Reference

Scan Tool Data List 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 yaw rate/lateral accelerometer connector.
2. Test the yaw rate/lateral sensor reference voltage circuit for a short to voltage, short to ground, an open or high resistance.
^ If the reference voltage circuit did not tests normal, repair the circuit.

3. Test the yaw/lateral sensor ground circuit for an open or high resistance.
^ If the reference ground circuit did not tests normal, repair the circuit.

4. Test the yaw/lateral sensor CAN HI and LO circuit for a short to voltage, short to ground, an open or high resistance.
^ If the yaw/later CAN HI and LO circuits did not test normal repair the circuit.

5. Ignition ON, test the yaw/lateral sensor reference voltage circuit for 12 volts, and the ground circuit for an open or high resistance.
^ If the yaw/later 12-volt reference and ground circuits test normal replace the yaw/lateral sensor.
^ If the yaw/later 12-volt reference and ground circuits did not test normal replace the EBCM.

Repair Instructions

Vehicle Yaw Sensor with Vehicle Lateral Accelerometer Replacement

Control Module References for EBCM

Repair Verification

Diagnostic Repair Verification