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.

Conditions for Running the DTC

C0035-C0050 00

C0035-C0050 0F

C0035-C0050 18

Conditions for Setting the DTC

C0035-C0050 00

An open or a short to ground is detected on the wheel speed sensor signal circuit by the EBCM.

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 18

The code is set when the following conditions exist:

Action Taken When the DTC Sets

If equipped, the following actions occur:

Diagnostic Aids

C0035-0050 18

Under the following conditions, 2 Wheel Speed Sensor Input is 0 and DTCs are set:

Diagnose each wheel speed sensor individually.

C0035-C0050 18, 0F, 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:

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

1. Ignition OFF, disconnect the harness connector at the suspect wheel speed sensor.
2. Ignition ON, test for ignition voltage between the signal circuit terminal B and ground.

⇒	If less than the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the EBCM.

3. Test for ignition voltage between the signal circuit terminal B and the low reference circuit terminal A.

⇒	If less than the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the EBCM.

4. Disconnect the harness connector at the EBCM.
5. Test for infinite resistance between the signal circuit terminal B and ground at the wheel speed sensor harness connector.

⇒	If not the specified value, test the signal circuit for a short to ground.

6. If all circuits test normal, test or replace the wheel speed sensor.

Component Testing

1. Ignition OFF, disconnect the harness connector at the suspect wheel speed sensor.
2. Connect a 3A fused jumper wire between B+ and the wheel speed sensor signal terminal A.
3. Test for 4-8 mA on the low reading between the low reference terminal B and ground when spinning the wheel very slow.

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

4. Test for 11-16 mA on the high reading between the low reference terminal B and ground when spinning the wheel very slow.

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

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.