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 CircuitDTC 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 Communication Circuit | C0186 00 | C0186 00 | C0186 00 | C0186 5A |
Lateral Accelerometer Communication Circuit | C0186 00 | C0186 00 | C0186 00 | C0186 5A |
Lateral Accelerometer Communication 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.
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. |
Reference Information
Schematic Reference
Antilock Brake System Schematics
Connector End View Reference
Antilock Brake System Connector End Views
Description and Operation
Electrical Information Reference
Scan Tool Reference
Scan Tool Data List for EBCM
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the Yaw Rate/Lateral Accelerometer sensor.
- Test for less than 1 ohm of resistance between the ground circuit terminal 1 and ground.
- Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 4 and ground.
- Ignition OFF, disconnect the harness connector at the EBCM.
- Ignition ON, test for 0 volts between the communication circuit terminal 37 and ground.
- Test for 0 volts between the communication circuit terminal 24 and ground.
- Ignition OFF, test for infinite resistance between the communication circuit terminal 37 and ground.
- Test for infinite resistance between the communication circuit terminal 24 and ground.
- Test for less than 1 ohm of resistance between the communication circuit terminals 24 and terminal 3.
- Test for less than 1 ohm of resistance between the communication circuit terminals 37 and terminal 2.
- Test for infinite resistance between the communication circuit 37 and the communication circuit 24.
- If all circuits test normal, replace the Yaw Rate/Lateral sensor.
| ⇒ | If greater than the specified range, test for an open/high resistance in the ground circuit. If the circuit tests normal, replace the EBCM. |
| ⇒ | 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. |
| ⇒ | If greater than the specified value, test the communication circuit for a short to voltage. |
| ⇒ | If greater than the specified value, test the communication circuit for a short to voltage. |
| ⇒ | If not the specified value, test the communication circuit for a short to ground. |
| ⇒ | If not the specified value, test the communication circuit for a short to ground. |
| ⇒ | If greater than the specified range, test the communication circuit for an open/high resistance. |
| ⇒ | If greater than the specified range, test the communication circuit for an open/high resistance. |
| ⇒ | If not the specified value, test the communication circuits for a short together. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for EBCM replacement, setup and programming |
