C0252

DTC C0252

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 Instructions provides an overview of each diagnostic category.

DTC Descriptor
DTC C0252 00
- Vehicle Stability Control Module Sensors Correlation

Circuit/System Description

The electronic brake control module (EBCM) controls the vehicle stability control system by monitoring the inputs from the yaw/lateral accelerometer sensor, wheel speed sensors and steering wheel angle sensor. All of the sensors need to correlate to the vehicle dynamics during the initial drive off in order to enable vehicle stability control. Normally this takes place within 100 meters (110 yards).

Conditions for Running the DTC

* Ignition ON.
* Ignition voltage is greater than 10 volts
* The steer wheel angle sensor has been centered.
* The vehicle stability control system has not been initialized.
* The direction (understeer or oversteer) of the yaw rate error has not changed.
* Vehicle is moving.

Conditions for Setting the DTC

* Vehicle is driven in a straight line without centering or initialization the stability control system.
* The yaw rate has not changed and the lateral acceleration is less than 0.5 g.

Action Taken When the DTC Sets

* The EBCM disables the ABS, traction control system and the vehicle stability enhancement system for the duration of the ignition cycle.
* The Stability indicators illuminate.
* A driver information center message and/or a warning indicator may be displayed.

Conditions for Clearing the DTC

* The condition for the DTC is no longer present or the ignition is cycled.
* The EBCM automatically clears the history DTC when a current DTC is not detected in 40 consecutive drive cycles.

Diagnostic Aids

* The DTC C0252 can be set if the vehicle has been driven above 8 km (5 mph) on a winding road prior to the vehicle stability control system initialization with the brake pedal applied and while accelerating.
* Driving off with constant steering wheel input or brake switch activation.
* An improperly mounted or loose combination yaw/lateral accelerometer sensor.
* Stuck brake switch.
* Improper steering alignment or tire pull.
* An internal yaw/lateral accelerometer sensor failure.
* An EBCM internal failure.

Reference Information
Schematic Reference

Antilock Brake System Schematics [1][2]Antilock Brakes / Traction Control Systems
Connector End View Reference

Component Connector End Views Hybrid/EV Battery Pack X1 A4
Description and Operation

ABS Description and Operation Description and Operation
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 Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON, verify that DTC C0186, C0196 or C0710 is not set.

• If DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.

2. Verify the B119 Multi-axis Acceleration Sensor is mounted properly.

• If not mounted properly, refer to Vehicle Yaw Sensor with Vehicle Lateral and Longitudinal Accelerometer Replacement Service and Repair.

3. Clear DTC, test drive vehicle under normal driving conditions.
4. Verify DTC C0252 is not set.

• If the DTC is set replace the K17 EBCM and verify the DTC does not reset. If the DTC resets, replace the Q5 brake pressure modulator valve assembly.

Repair Instructions

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

* Vehicle Yaw Sensor with Vehicle Lateral and Longitudinal Accelerometer Replacement Service and Repair
* Electronic Brake Control Module with Brake Pressure Modulator Valve Replacement Electronic Brake Control Module with Brake Pressure Modulator Valve Replacement
* Control Module References Control Module References for EBCM replacement, programming and setup