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.
The ignition is ON.
The compensated bias value of the lateral accelerometer is greater than 0.3 g.
The lateral accelerometer input voltage is less than 0.15 volts or greater than 4.85 volts for 1 second.
• | The EBCM disables the VSES for the duration of the ignition cycle. |
• | The DIC displays the Service Stability System message. |
• | The ABS/TCS remains functional. |
• | The condition for the DTC is no longer present and the DTC is cleared with a scan tool. |
• | The electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles. |
The following conditions can cause this concern:
• | Improper steering alignment. |
• | Open, short to ground, or short to voltage. |
• | Internal lateral accelerometer failure. |
• | EBCM internal failure. |
The numbers below refer to the step numbers on the diagnostic table.
Tests for the proper operation of the circuit in the low voltage range.
Tests for the proper operation of the circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to ground.
Tests for a short to voltage in the 5 volt reference circuit.
Tests the bias voltage of the lateral accelerometer sensor.
Step | Action | Values | Yes | No | ||||||
---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics Connector End View Reference: Antilock Brake System Connector End Views | ||||||||||
1 | Did you perform the ABS Diagnostic System Check? | -- | Go to Step 2 | |||||||
2 |
Does the scan tool display that the Lateral Accelerometer Input parameter is within the specified range? | 0.15-4.85 V | Go to Step 6 | Go to Step 3 | ||||||
Does the scan tool display that the Lateral Accelerometer Input parameter is less than the specified value? | 0.15 V | Go to Step 4 | Go to Step 10 | |||||||
Does the scan tool display that the Lateral Accelerometer Input parameter is greater than the specified value? | 4.85 V | Go to Step 5 | Go to Step 8 | |||||||
Does the voltage measure less the specified value? | 5 V | Go to Step 12 | Go to Step 7 | |||||||
Does the scan tool display the Lateral Accelerometer Input parameter is within the specified range? | 2.3-2.7 V | Go to Diagnostic Aids | Go to Step 11 | |||||||
7 | Test the 5 volt reference circuit of the lateral accelerometer sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 13 | ||||||
8 | Test the 5 volt reference circuit of the lateral accelerometer 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 16 | Go to Step 9 | ||||||
9 | Test the signal circuit of the lateral accelerometer 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 16 | Go to Step 13 | ||||||
10 | Test the signal circuit of the lateral accelerometer sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 13 | ||||||
11 |
Important: Removing battery voltage or ground from the EBCM will result in the following
conditions:
Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 12 | ||||||
12 | Inspect for poor connections at the harness connector of the lateral accelerometer sensor. 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 16 | Go to Step 14 | ||||||
13 | 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 16 | Go to Step 15 | ||||||
14 | Replace the lateral accelerometer sensor. Refer to Lateral Accelerometer Replacement . Did you complete the repair? | -- | Go to Step 16 | -- | ||||||
15 |
Important: Perform the setup procedure for the EBCM. An unprogrammed EBCM will result
in the following conditions:
Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Did you complete the repair? | -- | Go to Step 16 | -- | ||||||
16 |
Does the DTC reset? | -- | Go to Step 2 | System OK |