Without JL7

DTC C0186 (Without JL7)

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



DTC Descriptor
DTC C0186 00
- Lateral Accelerometer Circuit

DTC C0186 08
- Lateral Accelerometer Rate Signal Invalid

DTC C0186 09
- Lateral Accelerometer Rate of Change Above Threshold

DTC C0186 75
- Lateral Accelerometer Circuit Bias Level Out Of Range

DTC C0186 3B
- Lateral Accelerometer Internal Self Test Failed

DTC C0186 1A
- Lateral Accelerometer Circuit Bias Level Out Of Range




Diagnostic Fault Information






Circuit/System Description

The electronic brake control module (EBCM) uses the lateral accelerometer signal to determine the lateral forces acting on a vehicle during a turn or a skid. The EBCM uses the signal from the lateral accelerometer as one of the inputs to operate the vehicle stability enhancement system (VSES).


Conditions for Running the DTC


C0186 00, 09, and 1A
* The ignition is ON.
* Ignition voltage is greater than 8 volts.



C0186 08
* Ignition voltage is ON.
* Ignition voltage is greater than 8 volts.
* The vehicle speed is greater than 0 km/h (0 mph).



C0186 19
* Ignition voltage is ON.
* Ignition voltage is greater than 8 volts.
* The vehicle is stationary.



C0186 52
* Ignition voltage is ON.
* Ignition voltage is greater than 8 volts.
* DTC C0196 is not set.
* The yaw rate is less than 8 degrees per second.



Conditions for Setting the DTC

C0186 00, 09, and 1A

One of the following conditions exist:

* The lateral accelerometer signal voltage is less than 0.15 volt.
* The lateral accelerometer signal voltage is greater than 4.85 volts for 0.03 second.


C0186 08

The lateral accelerometer signal voltage increases less than 0.5 volt during the lateral accelerometer sensor self test.

C0186 09

The lateral accelerometer signal exceeds 11 g (0.39 oz) per second twice within 0.2 second.

C0186 19

The lateral acceleration is greater than 0.5 g (0.02 oz) for 1 second.

C0186 1A

Both of the following conditions exist:

* The compensated bias value of the lateral accelerometer sensor is greater than 0.3 g (0.01 oz).
* The yaw rate is centered.


C0186 52

The slip rate error exceeds 0.5 g (0.02 oz) 60 times within one drive cycle.


Action Taken When the DTC Sets

If equipped, the following actions will occur:

* The EBCM disables the VSES for the duration of the ignition cycle.
* The driver information center (DIC) displays the SERVICE STABILITY SYS message.
* The antilock brake system (ABS) and the traction control system (TCS) remain functional.



Conditions for Clearing the DTC

* The condition for setting the DTC is no longer present.
* The EBCM automatically clears a history DTC when a current DTC is not detected in 100 consecutive drive cycles.



Diagnostic Aids

The lateral accelerometer is packaged with the yaw rate sensor as a single component.


Reference Information
Schematic Reference

Antilock Brake System Schematics (Except JL7) (Antilock Brake System Schematics (Except RPO JL7))Antilock Brake System Schematics (JL7) (Antilock Brake System Schematics (With RPO JL7))
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

ABS Description and Operation (Without JL7) (ABS Description and Operation (Without RPO JL7))ABS Description and Operation (With JL7) (ABS Description and Operation (With RPO JL7))
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 Testing

1. Ignition OFF, disconnect the harness connector at the yaw and lateral acceleration sensor.
2. Test for less than 5 ohms between the low reference circuit terminal D 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 4.8-5.2 volts between the 5-volt reference circuit terminal B and ground.

• If less than the specified range, test the 5 volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the EBCM.


• If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the EBCM.

4. Verify the scan tool Lateral Accelerometer Signal parameter is less than 0 volts.

• If greater than the specified range, test the signal circuit terminal E for a short to voltage. If the circuit tests normal, replace the EBCM.

5. Install a 3A fused jumper wire between the signal circuit terminal E and the 5-volt reference circuit terminal B. Verify the scan tool Lateral Accelerometer Signal is greater than 4.8 volts.

• If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the EBCM.

6. If all circuits test normal, test or replace the yaw and lateral acceleration sensor.



Repair Instructions

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

* Vehicle Yaw Sensor with Vehicle Lateral Accelerometer Replacement (Yaw Sensor with Vehicle Lateral Accelerometer Replacement) (w/o MX7)
* Vehicle Yaw Sensor with Vehicle Lateral and Longitudinal Accelerometer Replacement (Yaw Sensor with Vehicle Lateral and Longitudinal Accelerometer Replacement) (MX7)
* Control Module References (Programming and Relearning) for EBCM replacement, setup, and programming