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

-
VSES Sensors Uncorrelated

Circuit/System Description

The electronic brake control module (EBCM) controls the vehicle stability enhancement system (VSES) by monitoring the inputs of the yaw rate/lateral accelerometer sensor, and steering wheel angle sensor. The readings are compared to an internal calibrated value so it knows if the vehicle is having an instability condition to activate the VSES. When the readings indicate a VSES event is occurring longer than 10 seconds is not possible under normal conditions. The yaw/lateral sensor is a combination sensor in one component.

Conditions for Running the DTC

* The steering angle has been centered.

* VSES is active.

Conditions for Setting the DTC

One of the following conditions exist:

* VSES is engaged for 10 seconds with the yaw rate error always in either understeer or oversteer.

* The yaw rate error is greater then 10 degrees/second for 5 seconds, and the yaw has not changed and the lateral acceleration is less than 0.5 g.

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 (TCS) and vehicle stability enhancement system (VSES) for the duration of the ignition cycle.

* The ABS indicator illuminates.

* The Stabilitrak indicator illuminates.

* The driver information center (DIC) displays All Wheel Drive Off/ Service Traction Control / Service Stabilitrak message.

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 following conditions can cause this concern:

* Improper steering alignment or tire pull

* An improperly mounted or loose combination yaw rate/lateral accelerometer sensor

* An internal yaw rate/lateral accelerometer failure

Reference Information

Schematic Reference

Antilock Brake System Schematics [1][2]Antilock Brakes / Traction Control Systems

Connector End View Reference

Component Connector End Views A/C Compressor Clutch

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 Programming and Relearning for scan tool information

Circuit/System Verification

Verify that DTC C0186, C0196, C0253, or C0710 is not set.

If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle