Diagnostic Instructions
DTC Descriptor
DTC C0252: Vehicle Stability Enhancement System (VSES) Sensors Uncorrected
Circuit Description
The vehicle stability enhancement system (VSES) is activated by the electronic brake control module (EBCM) calculating the desired yaw rate and comparing it to the actual yaw rate input. The desired yaw rate is calculated from measured steering wheel position,
vehicle speed, and lateral acceleration. The difference between the desired yaw rate and actual yaw rate is the yaw rate error, which is a measurement of oversteer or understeer. If the yaw rate error becomes too large, the EBCM will attempt to correct the vehicle
yaw motion by applying differential braking to the left or right wheels.
Conditions for Running the DTC
| • | The steer angle has been centered. |
| • | The direction, understeer or oversteer, of the yaw rate error has not changed. |
Conditions for Setting the DTC
One of the following conditions occur:
| • | The VSES is engaged for 10 seconds with the yaw rate error always in either understeer or oversteer. Under this condition, this DTC will set by itself. |
| • | The yaw rate error is greater than 10 degrees/second for 5 seconds. |
Action Taken When the DTC Sets
If equipped, the following actions occur:
| • | The EBCM disables the antilock brake system (ABS)/traction control system (TCS)/VSES and for the duration of the ignition cycle. |
| • | A malfunction DTC will set. |
| • | The ABS indicator turns ON. |
| • | The Stability Off indicator turns ON. |
Conditions for Clearing the DTC
| • | The condition for the DTC is no longer present. |
| • | A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present. |
Diagnostic Aids
Important: It is important to check the wiring harness connections to the following items:
| • | LF wheel speed sensor (WSS) |
| • | During diagnosis, park the vehicle on a level surface. |
| • | Inspect the vehicle for proper alignment. The car should not pull in either direction while driving straight on a level surface. |
| • | Find out from the customer the conditions under which the DTC was set. This information will help to duplicate the failure. |
| • | The Snapshot function on the scan tool can help find an intermittent DTC. |
Reference Information
Schematic Reference
Antilock Brake System Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
ABS Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References
for Scan Tool Information
Circuit/System Verification
Ignition ON, observe the ABS DTCS function in EBCM VSES scan tool data display.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
Diagnostic Test Drive
Repair Verification
Ignition ON, observe the ABS DTCS function in EBCM VSES scan tool data display.
