Diagnostic Instructions

DTC Descriptors

DTC C0186 00: Lateral Accelerometer Circuit Electrical Failure

DTC C0186 1A: Lateral Accelerometer Circuit Bias Level Out of Range

DTC C0186 3B: Lateral Accelerometer Circuit Internal Self Test Failed

DTC C0186 5A: Lateral Accelerometer Circuit Plausibility Failure

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Ignition Voltage	C0186 00	C0186 00	--	C0186 5A, C0186 3B, C0186 1A
Low Reference	C0186 00	C0186 00	C0186 00	C0186 5A, C0186 3B, C0186 1A
CAN Bus High Serial Data	C0186 00	C0186 00	C0186 00	C0186 5A, C0186 3B, C0186 1A
CAN Bus Low Serial Data	C0186 00	C0186 00	C0186 00	C0186 5A, C0186 3B, C0186 1A

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 yaw rate/lat sensor communicates with the EBCM via discrete CAN Bus High and CAN Bus Low serial data circuits.

Conditions for Running the DTC

Ignition ON.

Conditions for Setting the DTC

Action Taken When the DTC Sets

Conditions for Clearing the DTC

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

ABS Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the yaw rate/lat sensor.
2. Ignition OFF for 60 seconds, test for less than 5 ohms between the low reference circuit terminal 5 and ground.

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

3. Ignition ON, test for ignition voltage between the ignition voltage circuit terminal 3 and ground.

⇒	If not within the specified range, test the ignition voltage circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the EBCM.

4. Ignition OFF, disconnect the harness connector at the EBCM.
5. Ignition ON, test for less than 1 volt between the following terminal listed below and ground.

•	CAN Bus High serial data circuit terminal 18

•	CAN Bus Low serial data circuit terminal 19

⇒	If greater than the specified value, test the appropriate serial data circuit for a short to voltage. If the circuit tests normal, test or replace the yaw sensor/lateral accelerometer.

6. Ignition OFF, test for infinite resistance between the following terminal listed below and ground.

•	CAN Bus High serial data circuit terminal 18

•	CAN Bus Low serial data circuit terminal 19

⇒	If not the specified value, test the appropriate serial data circuit for a short to ground. If the circuit tests normal, test or replace the vehicle yaw sensor/lateral accelerometer.

7. Test for less than 2 ohms between the appropriate serial data circuit terminals listed below.

•	CAN Bus High serial data circuit terminal 18 at the EBCM harness connector and terminal 2 at the yaw/lat sensor harness connector.

•	CAN Bus Low serial data circuit terminal 19 at the EBCM harness connector and terminal 1 at the yaw/lat sensor harness connector.

⇒	If greater than the specified range, test the appropriate serial data circuit for an open/high resistance. If the circuit tests normal, replace the yaw sensor/lateral accelerometer.

8. Test for infinite resistance between the CAN Bus High serial data circuit terminal 18 and the CAN Bus Low serial data circuit terminal 19.

⇒	If not the specified value, repair the serial data circuits for a short together.

9. If all circuits test normal, replace the yaw rate/lat sensor. If DTC resets, replace the EBCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.