C0186

DTC C0186

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach. Initial Inspection and Diagnostic Overview
* 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/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.

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.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the Yaw Rate/Lateral Accelerometer sensor.
2. Test for less than 1 ohm of resistance between the ground circuit terminal 1 and ground.
^ If greater than the specified range, test for an open/high resistance in the ground circuit. If the circuit tests normal, replace the EBCM.

3. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 4 and ground.
^ If the test lamp does not illuminate, test the ignition circuit for a short to ground or an 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 0 volts between the communication circuit terminal 37 and ground.
^ If greater than the specified value, test the communication circuit for a short to voltage.

6. Test for 0 volts between the communication circuit terminal 24 and ground.
^ If greater than the specified value, test the communication circuit for a short to voltage.

7. Ignition OFF, test for infinite resistance between the communication circuit terminal 37 and ground.
^ If not the specified value, test the communication circuit for a short to ground.

8. Test for infinite resistance between the communication circuit terminal 24 and ground.
^ If not the specified value, test the communication circuit for a short to ground.

9. Test for less than 1 ohm of resistance between the communication circuit terminals 24 and terminal 3.
^ If greater than the specified range, test the communication circuit for an open/high resistance.

10. Test for less than 1 ohm of resistance between the communication circuit terminals 37 and terminal 2.
^ If greater than the specified range, test the communication circuit for an open/high resistance.

11. Test for infinite resistance between the communication circuit 37 and the communication circuit 24.
^ If not the specified value, test the communication circuits for a short together.

12. If all circuits test normal, replace the Yaw Rate/Lateral sensor.

Repair Instructions

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

* Vehicle Yaw Sensor with Vehicle Lateral Accelerometer Replacement
* Programming and Relearning Programming and Relearning