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 front wheel.
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 | Inspect the mounting of the yaw rate/lateral accelerometer sensor. Refer to Vehicle Yaw Sensor with Vehicle Lateral Accelerometer Replacement . Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 3 |
3 |
Does the scan tool display suddenly increase or decrease without rapid turning of the vehicle? | -- | Go to Step 4 | Go to Step 5 |
4 | Perform the diagnosis for DTC C0252. Refer to DTC C0252 . Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 12 |
5 |
Does the scan tool display change states as the steering wheel was rotated? | -- | Go to Step 6 | Go to Step 14 |
With the scan tool, perform the Steering Position Sensor Test. Did the SWPS pass the test? | -- | Go to Step 7 | Go to Step 14 | |
7 |
Does the scan tool display within the specified range? | 2.3-2.7 V | Go to Step 9 | Go to Step 8 |
8 | Replace the yaw rate/lateral accelerometer sensor. Refer to Vehicle Yaw Sensor with Vehicle Lateral Accelerometer Replacement . Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 9 |
9 | Inspect the electronic brake control module (EBCM) for the proper part number. Did you find the correct part number? | -- | Go to Step 10 | Go to Step 12 |
10 | Inspect the power steering gear for the proper part number. Did you find the correct part number? | -- | Go to Step 11 | Go to Step 13 |
11 | Inspect the alignment of the vehicle. Refer to Wheel Alignment Measurement . Did you find and correct the condition? | -- | Go to Step 15 | Go to Testing for Intermittent Conditions and Poor Connections |
12 | Replace the EBCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 15 | -- |
13 | Replace the power steering gear. Refer to Steering Gear Replacement . Did you complete the replacement? | -- | Go to Step 15 | -- |
14 | Replace the steering wheel position sensor (SWPS). Did you complete the replacement? | -- | Go to Step 15 | -- |
15 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 2 |
