Diagnostic Instructions

DTC Descriptors

DTC C0035 00: Left Front Wheel Speed Sensor Circuit No Additional Information

DTC C0035 0F: Left Front Wheel Speed Sensor Circuit Erratic Signal

DTC C0035 18: Left Front Wheel Speed Sensor Circuit Signal Amplitude Less Than Minimum

DTC C0040 00: Right Front Wheel Speed Sensor Circuit No Additional Information

DTC C0040 0F: Right Front Wheel Speed Sensor Circuit Erratic Signal

DTC C0040 18: Right Front Wheel Speed Sensor Circuit Signal Amplitude Less Than Minimum

DTC C0045 00: Left Rear Wheel Speed Sensor Circuit No Additional Information

DTC C0045 0F: Left Rear Wheel Speed Sensor Circuit Erratic Signal

DTC C0045 18: Left Rear Wheel Speed Sensor Circuit Signal Amplitude Less Than Minimum

DTC C0050 00: Right Rear Wheel Speed Sensor Circuit No Additional Information

DTC C0050 0F: Right Rear Wheel Speed Sensor Circuit Erratic Signal

DTC C0050 18: Right Rear Wheel Speed Sensor Circuit Signal Amplitude Less Than Minimum

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Left Front Sensor Signal	C0035 00	C0035 00	C0035 00	C0035 0F 18
Left Front Sensor Low Reference	C0035 00	C0035 00	C0035 00	C0035 0F 18
Right Front Sensor Signal	C0040 00	C0040 00	C0040 00	C0040 0F 18
Right Front Sensor Low Reference	C0040 00	C0040 00	C0040 00	C0040 0F 18
Left Rear Sensor Signal	C0045 00	C0045 00	C0045 00	C0045 0F 18
Left Rear Sensor Low Reference	C0045 00	C0045 00	C0045 00	C0045 0F 18
Right Rear Sensor Signal	C0050 00	C0050 00	C0050 00	C0050 0F 18
Right Rear Sensor Low Reference	C0050 00	C0050 00	C0050 00	C0050 0F 18

Circuit/System Description

The wheel speed sensor receives ignition voltage from the electronic brake control module (EBCM) and a ground through the chassis of the vehicle. As the wheel spins, the wheel speed sensor sends the EBCM a DC square wave signal. The EBCM uses the frequency of the square wave signal to calculate the wheel speed. When the EBCM sets a wheel speed sensor DTC, the engine control module (ECM) receives a serial data message of the fault detected and ECM sets a DTC and illuminates the MIL.

Conditions for Running the DTC

C0035-C0050 18

C0035-C0050 0F

C0035-C0050 00

Conditions for Setting the DTC

C0035-C0050 18

The code is set when the following conditions exist:

C0035-C0050 0F

If the EBCM detects a change in wheel speed that exceeds 20 km/h (12 mph) between two 10 millisecond wheel speed samples. If the condition occurs 3 times in 200 milliseconds, the code is set.

C0035-C0050 00

The code is set when either of the following conditions exist:

Action Taken When the DTC Sets

If equipped, the following actions occur:

Conditions for Clearing the DTC

Diagnostic Aids

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:

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 40 km/h (25 mph) for at least 30 seconds.
3. If the DTC returns, replace the suspected wheel speed sensor or repair the wheel speed sensor wiring.
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

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).

Circuit/System Testing

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

1. Ignition OFF, disconnect the harness connector at the EBCM.
2. Ignition ON, test for less than 1 volt between the low reference circuit terminal of the appropriate sensor listed below and ground .

•	LF Sensor circuit terminal A2

•	RF Sensor circuit terminal A4

•	LR Sensor circuit terminal A6

•	RR Sensor circuit terminal A8

⇒	If greater than the specified value, test the low reference circuit for a short to voltage. If the circuit tests normal, test or replace the wheel speed sensor.

3. Test for less than 1 volt between the signal circuit terminal of the appropriate sensor listed below and ground.

•	LF Sensor circuit terminal A1

•	RF Sensor circuit terminal A3

•	LR Sensor circuit terminal A5

•	RR Sensor circuit terminal A7

⇒	If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, test or replace the wheel speed sensor.

4. Ignition OFF, test for infinite resistance between the low reference terminal of the appropriate sensor listed below and ground.

•	LF Sensor circuit terminal A2

•	RF Sensor circuit terminal A4

•	LR Sensor circuit terminal A6

•	RR Sensor circuit terminal A8

⇒	If less than the specified value, test the low reference circuit for a short to ground. If the circuit tests normal, test or replace the wheel speed sensor.

5. Test for infinite resistance between the following signal circuit terminal of the appropriate sensor listed below and ground.

•	LF Sensor circuit terminal A1

•	RF Sensor circuit terminal A3

•	LR Sensor circuit terminal A5

•	RR Sensor circuit terminal A7

⇒	If less than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, test or replace the wheel speed sensor.

6. Ignition OFF, disconnect the harness connector at the appropriate wheel speed sensor.
7. Ignition OFF, test for less than 2 ohms between the appropriate low reference circuit terminals listed below.

•	LF Sensor circuit terminal A2 at the EBCM harness connector and terminal B at the WSS harness connector.

•	RF Sensor circuit terminal A4 at the EBCM harness connector and terminal B at the WSS harness connector.

•	LR Sensor circuit terminal A6 at the EBCM harness connector and terminal B at the WSS harness connector.

•	RR Sensor circuit terminal A8 at the EBCM harness connector and terminal B at the WSS harness connector.

⇒	If greater than the specified value, test the low reference circuit for an open or high resistance. If the circuit tests normal, test or replace the wheel speed sensor.

8. Test for less than 2 ohms between the appropriate signal circuit terminals listed below.

•	LF Sensor circuit terminal A1 at the EBCM harness connector and terminal A at the WSS harness connector.

•	RF Sensor circuit terminal A3 at the EBCM harness connector and terminal A at the WSS harness connector.

•	LR Sensor circuit terminal A5 at the EBCM harness connector and terminal A at the WSS harness connector.

•	RR Sensor circuit terminal A7 at the EBCM harness connector and terminal A at the WSS harness connector.

⇒	If greater than the specified value, test the signal circuit for an open or high resistance. If the circuit tests normal, test or replace the wheel speed sensor.

9. If all circuits test normal, replace the EBCM.

Component Testing

1. Ignition OFF, disconnect the harness connector at the wheel speed sensor.
2. Connect a test lamp between B+ and the wheel speed sensor signal terminal A.
3. Connect a DMM between the low reference terminal B and ground. Set up the DMM to measure mA using the DC scale.
4. Spin the wheel very slowly. Using the DMM MIN/MAX feature, test for 4-8mA on the MIN capture and 12-16mA on the MAX capture.

⇒	If not within the specified range, replace the wheel speed sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.