Circuit Description
The vehicle stability enhancement system (VSES) is activated when the EBCM determines that the desired yaw rate does not match the actual yaw rate. The desired yaw rate is calculated from the measured steering wheel position, vehicle speed, and lateral acceleration.
The usable output voltage range is 0.15-4.85 volts for the following sensors:
| • | The yaw rate sensor |
| • | The longitudinal accelerometer |
The usable output voltage range is 0.4-4.6 volts for the lateral accelerometer.
With no sensor bias present, a 2.5 volt signal from these sensors is interpreted by the EBCM respectively as follows:
| • | Zero yaw rate |
| • | Zero lateral acceleration |
| • | Zero longitudinal acceleration |
The sensor bias compensates, during VSES initialization, for sensor mounting alignment errors, electronic signal errors, temperature changes, and manufacturing differences.
Conditions for Running the DTC
C0217, C0218, C0219
The ignition is ON.
C0220
| • | The ABS/VSES is not active. |
| • | A rough road condition is not detected. |
| • | The vehicle is not in reverse or neutral. |
| • | The speed of the vehicle is greater than 5 km/h (3 mph). |
| • | The vehicle is being driven in a relatively straight line, making no abrupt maneuvers. |
Conditions for Setting the DTC
C0217
The signal voltage of the longitudinal accelerometer is less than 0.15 volts or greater than 4.85 volts for 200 milliseconds.
C0218
The longitudinal accelerometer signal indicates a sudden change in longitudinal acceleration which exceeds a physical limitation.
C0219
The longitudinal accelerometer signal indicates the longitudinal accelerometer bias voltage is out of normal operating range.
C0220
The longitudinal accelerometer signal indicates a change in longitudinal acceleration which does not correlate with the signals from other sensors.
Action Taken When the DTC Sets
| • | The EBCM disables the VSES. |
| • | The message center displays the SERVICE STABILITY SYSTEM message. |
Conditions for Clearing the DTC
The conditions for setting the DTC are no longer present and you use the scan tool Clear DTCs function.
Diagnostic Aids
| • | Inspect the vehicle for proper wheel alignment. Ensure the vehicle does not pull toward the left or right while driving straight forward on a level surface. |
| • | Communicate with the customer to determine the conditions under which the message center displays the Service Stability System message. Learning the conditions under which the DTC sets may help you duplicate the failure. |
| • | Use the Snapshot function on the scan tool in order to assist you in locating an intermittent malfunction. |
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics | |||
1 | Did you perform the ABS Diagnostic System Check? | Go to Step 2 | |
2 |
Does the DTC reset? | Go to Step 3 | Go to Diagnostic Aids |
3 |
Important: Following EBCM replacement, use the scan tool to perform the Tire Size Calibration procedure. Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Did you complete the replacement? | Go to Step 4 | -- |
4 |
Does the DTC reset? | Go to Step 2 | System OK |
