For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using the 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
DTC C0186 5A: Lateral Accelerometer Circuit Erratic

### 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
Lateral Accelerometer CAN Bus Low Circuit | C0186 00 | C0186 00 | C0186 00 | C0186 5A
Lateral Accelerometer Ground Circuit | -- | C0186 00 | -- | --

### Circuit/System Description

The electronic brake control module (EBCM) supplies 5 V to the yaw-rate sensor reference circuit and a ground through the yaw-rate sensor low reference circuit, which is shared with the steering angle sensor. The EBCM, yaw-rate sensor assembly and steering angle sensor share a common 12 V supply voltage circuit.

The lateral acceleration sensor produces signal output voltage that corresponds to the vehicle lateral acceleration.

### Conditions for Running the DTC

The ignition switch is in the ON position.

### Conditions for Setting the DTC

• | The EBCM detects a fault in the lateral acceleration signal voltage output.

• | Both brake lamps are faulty.

### Action Taken When the DTC Sets

One or more of the following actions may occur:

• | The EBCM disables ESP for the duration of the ignition cycle.

• | The ABS/TCS indicators turn ON.

• | The Trac-Off indicator turns ON.

### 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

Component 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 15 km/h (9 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 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/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/lateral 5 volt reference and ground circuits test normal replace the yaw/lateral sensor.

⇒ | If the yaw/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.

Control Module References for EBCM