• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Perform the prior to using this diagnostic procedure.
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Left Front Sensor Signal | C0035 00 | C0035 00 | C0035 00 | C0035 0F, C0035 18 |
Left Front Sensor Low Reference | C0035 00 | C0035 00 | C0035 00 | C0035 0F, C0035 18 |
Left Rear Sensor Signal | C0045 00 | C0045 00 | C0045 00 | C0045 0F, C0045 18 |
Left Rear Sensor Low Reference | C0045 00 | C0045 00 | C0045 00 | C0045 0F, C0045 18 |
Right Front Sensor Signal | C0040 00 | C0040 00 | C0040 00 | C0040 0F, C0040 18 |
Right Front Sensor Low Reference | C0040 00 | C0040 00 | C0040 00 | C0040 0F, C0040 18 |
Right Rear Sensor Signal | C0050 00 | C0050 00 | C0050 00 | C0050 0F, C0050 18 |
Right Rear Sensor Low Reference | C0050 00 | C0050 00 | C0050 00 | C0050 0F, C0050 18 |
As the wheel spins, the wheel speed sensor produces an alternating current (AC) signal. The electronic brake control module (EBCM) uses the frequency of the AC signal to calculate the wheel speed.
• | The ignition is ON. |
• | Ignition voltage is greater than 8 volts. |
• | The brake pedal is not pressed. |
• | No other wheel speed circuit DTCs are set. |
• | Two or three other wheel speeds are not 0 km/h. |
• | The ignition is ON. |
• | Ignition voltage is greater than 8 volts. |
• | The brake pedal is not pressed. |
• | A DTC is not set for the other wheel speed circuit on the same axle. |
• | The ignition is ON. |
• | Ignition voltage is greater than 8 volts. |
The code is set when the following conditions exist:
• | One wheel speed is 0 km/h. |
• | The remaining wheel speeds are greater than 8 km/h (5 mph). |
• | The difference between the remaining wheel speeds is less than 11 km/h (7 mph) from each other. |
The code is set when both of the following conditions exist:
• | The EBCM detects a change in wheel speed that exceeds 20 km/h (12 mph) between two 10 millisecond wheel speed samples. |
• | The condition occurs 3 times in 200 milliseconds. |
The code is set when either of the following conditions exist:
• | An open or a short to ground is detected on the wheel speed sensor signal circuit by the EBCM. |
• | A short to voltage is detected on the wheel speed sensor signal circuit by the EBCM. |
If equipped, the following actions occur:
• | The EBCM disables the antilock brake system (ABS) and the traction control system (TCS) for the duration of the ignition cycle. |
• | The ABS indicator turns ON. |
• | The vehicle dynamics caution (VDC) indicator turns ON. |
• | If the other wheel speed sensor on the same axle sets an additional DTC, the EBCM disables the dynamic rear proportioning (DRP) for the duration of the ignition cycle. |
• | When the EBCM disables DRP, the red brake warning indicator turns ON. |
Under the following conditions, 2 wheel speed sensors input are 0 and DTCs are set:
• | The 2 suspect wheel speeds equal zero for 6 seconds. |
• | The other wheel speeds are greater than 16 km/h (10 mph). |
• | The other wheel speeds are within 11 km/h (7 mph) of each other. |
Diagnose each wheel speed sensor individually.
If the customer comments that the ABS indicator is ON only during moist environmental conditions: rain, snow, vehicle wash, etc., inspect the wheel speed sensor wiring for signs of water intrusion. If the DTC is not current, clear all DTCs and simulate the effects of water intrusion by using the following procedure:
Antilock Brake System Schematics
Control Module References for scan tool information
Observe the scan tool Wheel Speed Sensor parameter. The reading should be the same speed on all sensors when driving in a straight line at a speed greater than 20 km/h (13 mph).
Important: Component Testing is performed before Circuit Testing when diagnosing wheel speed sensors.
⇒ | If not within the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the EBCM. |
⇒ | If not within the specified range, test the low reference circuit for a short to voltage. If the circuit tests normal, replace the EBCM. |
⇒ | If not the specified value, test the signal circuit for a short to ground. |
⇒ | If not within the specified range, test the signal circuit for an open or a high resistance. |
⇒ | If not within the specified range, test the low reference circuit for an open or a high resistance. |
⇒ | If not within the specified range, replace the wheel speed sensor. |
⇒ | If less than the specified value, replace the appropriate wheel speed sensor. |
⇒ | If less than the specified range, replace the wheel speed sensor. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for EBCM replacement, setup, and programming |