For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions 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 | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Lateral Accelerometer Supply Voltage Circuit | C0186 00 | C0186 00 | C0186 00 | --
Lateral Accelerometer CAN Bus High Circuit | C0186 00 | C0186 00 | C0186 00 | C0186 5A, 3B, 1A
Lateral Accelerometer CAN Bus Low Circuit | C0186 00 | C0186 00 | C0186 00 | C0186 5A, 3B, 1A
Lateral Accelerometer Ground Circuit | -- | C0186 00 | -- | --

### 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

#### Connector End View Reference

Antilock Brake System Connector End Views

#### 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 test 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 test 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 rate/lateral CAN HI and LO circuits did not test normal repair the circuit.

5. Ignition ON, test the yaw/lateral sensor reference voltage circuit for 5 volts, and the ground circuit for an open or high resistance.

⇒ | If the yaw rate/lateral 5-volt reference and ground circuits test normal replace the yaw/lateral sensor.

⇒ | If the yaw rate/lateral 5-volt reference and ground circuits did not test normal replace the EBCM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Electronic Brake Control Module Replacement

• | Control Module References for EBCM replacement, setup, and programming