C0186
DTC C0186
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 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/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
* 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
* The EBCM disables the VSES for the duration of the ignition cycle.
* A DIC message and/or a warning indicator may be displayed.
Conditions for Clearing the DTC
* The condition for the DTC is no longer present.
* The EBCM clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.
Reference Information
Schematic Reference
Antilock Brake System Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
ABS Description and Operation (Description and Operation)
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 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.
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.
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.
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.
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.
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 the DTC resets, replace the EBCM.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
Control Module References (Programming and Relearning)for EBCM replacement, setup, and programming