Antilock Brake System - Non-Hybrid Less than 3900 kg (8600 lb) GVW
DTC C0186 or C0196
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructionsprovides an overview of each diagnostic category.
DTC Descriptors
DTC C0186 00
- Lateral Accelerometer Circuit
DTC C0186 5A
- Lateral Accelerometer Circuit Not Plausible
DTC C0196 00
- Yaw Rate Circuit
DTC C0196 5A
- Yaw Rate Circuit Not Plausible
Diagnostic Fault Information
Circuit/System Description
The yaw rate and the lateral accelerometer 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 EBCM supplies the 12 V to the yaw/lateral accelerometer sensor. The yaw/lateral accelerometer sensor communicates with the EBCM via discrete CAN Bus High and CAN Bus Low serial data circuits.
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
* The yaw/lateral accelerometer sensor fails an internal self test.
* Incorrectly mounted yaw/lateral accelerometer sensor.
* The correlation error between the yaw/lateral accelerometer sensor and steering wheel angle sensor.
Action Taken When the DTC Sets
One or more of the following actions may occur:
* The EBCM disables the antilock brake system (ABS), traction control system and vehicle stability enhancement system for the duration of the ignition cycle.
* The ABS indicator illuminates.
* The red Brake warning indicator illuminates.
* The Stabilitrak indicator illuminates.
* The driver information center displays All Wheel Drive Off/Service Traction Control/Service Stabilitrak message, if equipped.
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 40 consecutive drive cycles.
Note: During normal diagnostic and/or repair verification technicians may find that the ABS, Traction Control and/or Stabilitrak indicators may be ON with NO DTCs displayed by the EBCM. Do not replace the EBCM for this condition.
If the ABS, Traction Control and/or Stabilitrak telltales are ON with no DTCs set, perform the following steps:
1. Remove the key from the ignition, open and close the driver's door to turn off retained accessory power (RAP), and wait 60 seconds.
2. Ignition ON, if the ABS, Traction Control and/or Stabilitrak telltales are still illuminated, operate the vehicle at speeds greater than 15 km/h (10 mph) to complete the self test. The EBCM should request all telltale indicators to turn OFF.
3. If the telltales remain ON with no DTCs set after the drive cycle, disconnect the battery for at least 60 seconds then reconnect the battery.
4. Operate the vehicle at speeds greater than 40 km/h (25 mph), the EBCM should request all telltale indicators to turn OFF.
Diagnostic Aids
* The EBCM will shut down if it detects a fault or sets a DTC.
* An incorrectly mounted sensor can set a DTC.
Reference Information
Schematic Reference
Antilock Brake System Schematics Non-Hybrid Less than 3900 kg (8600 lb) GVW
Connector End View Reference
Component Connector End Views Connector End Views By Name
Description and Operation
ABS Description and Operation ABS (Non-Hybrid Less than 3900 kg (8600 lb) GVW)
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Programming and Relearningfor scan tool information
Circuit/System Testing
1. Verify that DTC U2142 is not set.
• If the DTC is set, refer to DTC U2105-U2199 U2105.
2. Verify that DTC C0710 is not set.
• If the DTC is set, refer to DTC C0710 Antilock Brake System - Non-Hybrid Less than 3900 kg (8600 lb) GVW.
3. Ignition OFF, disconnect the harness connector at the yaw/lateral accelerometer sensor.
4. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 10 ohm between the ground circuit terminal 1 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
5. Disconnect the harness connector at the EBCM.
6. Test for infinite resistance between the 12 V reference circuit terminal 32 of the EBCM connector and ground.
• If not the specified value, test the 12 V reference circuit for a short to ground.
7. Test for less than 2 ohm between the 12 V reference circuit terminal 32 of the EBCM connector and terminal 4 of the yaw/lateral accelerometer sensor connector.
• If greater than the specified range, test the 12 V reference circuit for open/high resistance.
8. If all circuits test normal, replace the yaw/lateral accelerometer sensor. If the DTC resets, replace the EBCM.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Vehicle Yaw Sensor with Vehicle Lateral Accelerometer Replacement Non-Hybrid Greater than/Equal to 3900 kg (8600 lb) GVW
* Control Module References Programming and Relearningfor EBCM replacement, programming and setup