Circuit/System 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's yaw motion by applying differential braking to the left or right front
wheel.
Reference Information
Schematic Reference
Antilock Brake System Schematics
Connector End View Reference
Component Connector End Views
Electrical Information Reference
Scan Tool Reference
Control Module References
Circuit/System Testing
- Inspect the mounting of the yaw rate sensor/lateral accelerometer.
⇒ | If the mounting of the yaw rate sensor/lateral accelerometer was incorrect or
loose repair as required.. |
- Install a scan tool.
- Perform the Diagnostic Test Drive and observe the Yaw Rate Sensor Input
parameter in the VSES data list.
⇒ | If the scan tool display suddenly increased or decreased without rapid turning
of the vehicle, perform the diagnosis for DTC C0196. |
⇒ | If a condition was not found in the diagnosis for DTC C0196, replace
the EBCM. |
- Straighten the front wheels.
- Slowly rotate the steering wheel in both directions and observe the Dual
Analog Steering Position Sensor Test (SWPS) Input A and Dual Analog SWPS Input B
in the DRP/ABS/TCS data list.
⇒ | If the scan tool display DID NOT change states as the steering wheel was rotated,
replace the steering angle sensor (SAS). |
- Perform the Steering Position Sensor Test in order to verify if the steering
angle sensor (SAS) is operating properly.
⇒ | If the SAS DID NOT pass the test, replace the SAS. |
- Place the vehicle on a level surface and observe the Lateral Accelerometer
Input parameter in the VSES data list to verify that the Lateral Accelerometer Input
parameter is within the valid range.
⇒ | If the scan tool DID NOT display within the specified range, replace the yaw
rate sensor/lateral accelerometer. |
- Inspect the electronic brake control module (EBCM) for the correct part
number.
⇒ | If the EBCM is not the correct part number, replace the EBCM. |
- Inspect the power steering gear for the correct part number.
⇒ | If the power steering gear is not the correct part number, replace the EBCM. |
- Inspect the wheel alignment of the vehicle.
⇒ | If the wheel alignment of the vehicle is outside of manufacturer specifications,
perform a wheel alignment on the vehicle.. |
Repair Instructions