Diagnostic Instructions
| • | 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. |
DTC Descriptors
DTC C0035 00: Left Front Wheel Speed Sensor Circuit MalfunctionDTC C0036 00: Left Front Wheel Speed Sensor Circuit Range Performance
DTC C0040 00: Right Front Wheel Speed Sensor Circuit Malfunction
DTC C0041 00: Right Front Wheel Speed Sensor Circuit Range Performance
DTC C0045 00: Left Rear Wheel Speed Sensor Circuit Malfunction
DTC C0046 00: Left Rear Wheel Speed Sensor Circuit Range Performance
DTC C0050 00: Right Rear Wheel Speed Sensor Circuit Malfunction
DTC C0051 00: Right Rear Wheel Speed Sensor Circuit Range Performance
Diagnostic Fault Information
Circuit | Short to Ground | Open or High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Left Front Sensor Signal | C0035 00, C0036 00 | C0035 00, C0036 00 | C0035 00, C0036 00 | C0035 00, C0036 00 |
Left Front Sensor Low Reference | C0035 00, C0036 00 | C0035 00, C0036 00 | C0035 00, C0036 00 | C0035 00, C0036 00 |
Right Front Sensor Signal | C0040 00, C0041 00 | C0040 00, C0041 00 | C0040 00, C0041 00 | C0040 00, C0041 00 |
Right Front Sensor Low Reference | C0040 00, C0041 00 | C0040 00, C0041 00 | C0040 00, C0041 00 | C0040 00, C0041 00 |
Left Rear Sensor Signal | C0045 00, C0046 00 | C0045 00, C0046 00 | C0045 00, C0046 00 | C0045 00, C0046 00 |
Left Rear Sensor Low Reference | C0045 00, C0046 00 | C0045 00, C0046 00 | C0045 00, C0046 00 | C0045 00, C0046 00 |
Right Rear Sensor Signal | C0050 00, C0051 00 | C0050 00, C0051 00 | C0050 00, C0051 00 | C0050 00, C0051 00 |
Right Rear Sensor Low Reference | C0050 00, C0051 00 | C0050 00, C0051 00 | C0050 00, C0051 00 | C0050 00, C0051 00 |
Circuit/System Description
As the wheel spins, the wheel speed sensor produces an AC signal. The electronic brake control module (EBCM) uses the frequency of the AC signal to calculate the wheel speed.
Conditions for Running the DTC
C0035 00, C0040 00 C0045 00, C0050 00
Ignition ON.
C0036 00, C0041 00, C0046 00, C0051 00
| • | The vehicle speed is over 40 km/h (25 mph) |
| • | The brake pedal is not pressed. |
| • | The ABS is not active. |
Conditions for Setting the DTC
C0035 00, C0040 00, C0045 00, C0050 00
A short to B+, short to ground, or an open/high resistance wheel speed sensor signal circuit exists for 0.02 seconds.
C0036 00, C0041 00, C0046 00, C0051 00
All of the following conditions exists for 0.01 second:
| • | The suspect wheel speed sensor equals zero. |
| • | The other wheel speeds are greater than 40 km/h (25 mph) for 0.01 second. |
| • | The suspect wheel equals zero during drive off, and the other wheels are greater than 18 km/h (11 mph). |
| • | A short to ground the wheel speed sensor is shorted to ground |
| • | A deviation of two wheel speed sensors at either side of the vehicle greater than 6 km/h (4 mph), or at the front axle greater than 10 km/h (6 mph) for a period of 10 to 20 seconds. |
Action Taken When the DTC Sets
| • | The EBCM disables the ABS/traction control system (TCS)/vehicle stability enhancement system (VSES) for the duration of the ignition cycle. |
| • | The ABS indicator illuminates. |
| • | The Traction Control indicator illuminates. |
| • | The driver information center (DIC) displays Service Stability System. |
Conditions for Clearing the DTC
| • | The condition for setting the DTC is no longer present. |
| • | The EBCM clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles. |
Diagnostic Aids
| • | A damaged rear wheel speed sensor ring can cause a DTC to set. |
| • | If 2 or more wheel speed sensors are inoperative diagnose each wheel speed sensor individually. |
C0035 00, C0040 00, C0045 00, C0050 00, C0051 00
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:
- Spray the suspected area with a 5 percent saltwater solution. To create a 5 percent saltwater solution, add 2 teaspoons of salt to 8 fl oz of water (10 g of salt to 200 ml of water).
- Test drive the vehicle over various road surfaces: bumps, turns, etc., above 40 km/h (25 mph) for at least 30 seconds.
- Rinse the area thoroughly when completed.
Reference Information
Schematic Reference
Antilock Brake System Schematics
Connector End View Reference
Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
With scan tool installed drive the vehicle in a straight line at a speed greater than 40 km/h (25 mph), all wheel speed sensors should read the same miles per hour.
Circuit/System Testing
Important: Component Testing is performed before Circuit Testing when diagnosing wheel speed sensors.
- Ignition OFF, disconnect the EBCM connector.
- Ignition ON, measure for 0 volt between the sensor signal circuit terminal or the low reference circuit terminal and ground at the EBCM connector.
- Ignition OFF, measure for infinite ohms between the wheel speed sensor signal or the low reference circuit and ground at the EBCM connector.
- Measure for 800-1600 ohms between the wheel speed sensor signal and low reference circuits at the EBCM connector.
- If all circuits test normal replace the EBCM.
| ⇒ | If over 0 volt, repair short to voltage or shorted together in sensor signal circuit or the low reference circuit. |
| ⇒ | If less than infinite ohms, repair short to ground in the sensor signal or the low reference circuit. |
| ⇒ | If greater than 1600 ohms test for an open/high resistance in the circuit or faulty wheel speed sensor. |
| ⇒ | If less than 800 ohms test for a short between the circuits or faulty wheel speed sensor. |
Component Testing
- Ignition OFF, disconnect the harness connector at the appropriate wheel speed sensor.
- Test for 850-1350 ohms between the signal terminal A and the low reference signal terminal B. During the test, check for an intermittent circuit condition by gentle moving the wheel speed sensor pigtail harness.
- Test for infinite resistance between each terminal and the steering knuckle. Reverse the test leads, test for infinite resistance between each terminal and the steering knuckle again.
- Spin the wheel while monitoring the voltage between the signal terminal A and the low reference terminal B. The voltage should be greater than 100 mV AC.
| ⇒ | 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. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for EBCM replacement, setup, and programming |
