Diagnostic Instructions

DTC Descriptors

DTC C0035: Left Front Wheel Speed Sensor Circuit

DTC C0036: Left Front Wheel Speed Sensor Circuit Range/Performance

DTC C0037: Left Front Wheel Speed Sensor Circuit Low

DTC C0040: Right Front Wheel Speed Sensor Circuit

DTC C0041: Right Front Wheel Speed Sensor Circuit Range/Performance

DTC C0042: Right Front Wheel Speed Sensor Circuit Low

DTC C0046: Left Rear Wheel Speed Sensor Circuit Range/Performance

DTC C0047: Left Rear Wheel Speed Sensor Circuit Low

DTC C0051: Right Rear Wheel Speed Sensor Circuit Range/Performance

DTC C0052: Right Rear Wheel Speed Sensor Circuit Low

Diagnostic Fault Information

Circuit	Short to Ground	Open or High Resistance	Short to Voltage	Signal Performance
Left Front Sensor Signal	C0035 C0037	C0035	C0035	C0036
Left Front Sensor Low Reference	C0035	C0035	C0035	C0036
Right Front Sensor Signal	C0040 C0042	C0040	C0040	C0040 C0041
Right Front Sensor Low Reference	C0040 C0042	C0040	C0040	C0040
Left Rear Sensor Signal	C0046 C0047	C0046	C0046	C0046
Left Rear Sensor Low Reference	C0046	C0046	C0046	C0046
Right Rear Sensor Signal	C0051 C0052	C0051	C0051	C0051
Right Rear Sensor Low Reference	C0051	C0051	C0051	C0051

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, C0040, C0045 and C0050

The ignition is ON.

C0036, C0037, C0041, C0042, C0046, C0047, C0051 and C0052

Conditions for Setting the DTC

C0035, C0040, C0045 and C0050

The EBCM detects an open or shorted wheel speed sensor circuit.

C0035, C0041, C0046 and C0051

The EBCM detects an erratic signal from the corresponding wheel speed sensor.

C0037, C0042, C0047 and C0052

The corresponding wheel speed sensor signal is 0 km/h (0 mph).

Action Taken When the DTC Sets

If equipped, the following actions occur.

Conditions for Clearing the DTC

The condition for setting the DTC is no longer present and the DTC is cleared with a scan tool.

Diagnostic Aids

If debris is present between the teeth of the tone ring, the wheel speed sensor could be moved out of position and the air gap could become too large. Adjust the air gap if any debris is found on the tone ring. Thoroughly inspect connections or circuitry that may cause an intermittent malfunction.

If the customer concern is that the ABS indicator is ON only during humid conditions such as rain, snow, or vehicle wash, thoroughly inspect the wheel speed sensor circuits for signs of water intrusion. Use the following procedure in order to help isolate the problem area:

1. 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).
2. Test drive the vehicle over various road surfaces: bumps, turns, etc., above 19 km/h (12 mph) for at least 30 seconds.
3. Repair or replace the suspect harness if the DTC sets.
4. Rinse the area thoroughly when completed.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

ABS 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 8 km/h (5 mph), all wheel speed sensors should read the same miles per hour.

Circuit/System Testing

Important: It is recommend that Component Testing is performed before Circuit Testing when diagnosing wheel speed sensors.

1. With the ignition OFF, disconnect the EBCM connector.
2. With the ignition ON, measure for 0 volt between the sensor signal circuit terminal or the low reference circuit and ground at the EBCM connector.

⇒	If over 0 volt, repair short to voltage in sensor signal circuit or the low reference circuit.

3. With the ignition OFF, measure for infinite ohms between the wheel speed sensor signal or the low reference circuit and ground at the EBCM connector.

⇒	If less than infinite ohms, repair short to ground in the sensor signal or the low reference circuit.

4. Measure for 1800-2200 ohms between the wheel speed sensor signal and low reference circuits at the EBCM connector.

⇒	If greater than 2200 ohms test for an open/high resistance in the circuit or faulty wheel speed sensor.

⇒	If less than 1800 ohms test for a short between the circuits or faulty wheel speed sensor.

5. If all circuits test normal replace the EBCM.

Component Testing

1. Disconnect the wheel speed sensor connector.
2. With the ignition OFF, measure for 1800-2200 ohms across the wheel speed sensor.

⇒	If the resistance is not between 1800-2200 ohms replace the faulty wheel speed sensor.

3. Spin the wheel. Measure across the wheel speed sensor for 800 mv AC or greater.

⇒	If the AC voltage is less than 800 mv replace the wheel speed sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.