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
C0209 and C0210
The ignition is ON.
C0211
The vehicle is driven straight forward at a speed greater than 19 km/h (12 mph) for more than 20 seconds.
C0212
The vehicle is driven straight forward at a speed greater than 19 km/h (12 mph) for at least 10 seconds prior to making a stable turning maneuver.
Conditions for Setting the DTC
C0209
The yaw rate sensor signal is less than 0.15 volts or greater than 4.85 volts for 20 milliseconds.
C0210
The yaw rate sensor signal indicates a sudden change in yaw rate which exceeds a physical limitation.
C0211
The yaw rate sensor signal indicates the yaw rate sensor bias voltage is out of normal operating range.
C0212
The yaw rate sensor signal indicates a change in yaw rate 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. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests the sensor circuitry in the high voltage range.
-
This step tests the sensor circuitry in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.
-
This step tests the 5-volt reference circuit of the yaw rate sensor/lateral accelerometer.
Step | Action | Values | 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 | ||||||
Is the Yaw Rate Sensor Input greater than the specified value? | 4.75 V | Go to Step 4 | Go to Step 7 | |||||||
Is the Yaw Rate Sensor Input less than the specified value? | 0.15 V | Go to Step 5 | Go to Step 8 | |||||||
Does the voltage measure greater than the specified value? | 4.75 V | Go to Step 10 | Go to Step 6 | |||||||
6 | Test the 5-volt reference circuit of the yaw rate sensor/lateral accelerometer for the following conditions.
Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 11 | ||||||
7 | Test the signal circuit of the yaw rate sensor for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 11 | ||||||
8 | Test the signal circuit of the yaw rate sensor for the following conditions.
Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 9 | ||||||
9 | Test the low reference circuit of the yaw rate sensor/lateral accelerometer for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 11 | ||||||
10 |
Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 12 | ||||||
11 | Inspect for poor connections at the harness connector of the EBCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 13 | ||||||
12 | Replace the yaw rate sensor/lateral accelerometer. Refer to Vehicle Yaw Sensor with Vehicle Lateral Accelerometer Replacement . Did you complete the replacement? | -- | Go to Step 14 | -- | ||||||
13 |
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 14 | -- | ||||||
14 |
Does the DTC reset? | -- | Go to Step 3 | System OK | ||||||
