Diagnostic Instructions

DTC Descriptors

DTC C0035 01: Left Front Wheel Speed Sensor Circuit Short to Battery

DTC C0035 02: Left Front Wheel Speed Sensor Circuit Short to Ground

DTC C0035 04: Left Front Wheel Speed Sensor Circuit Open

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

DTC C0035 26: Left Front Wheel Speed Sensor Circuit Signal Frequency Too Low

DTC C0040 01: Right Front Wheel Speed Sensor Circuit Short to Battery

DTC C0040 02: Right Front Wheel Speed Sensor Circuit Short to Ground

DTC C0040 04: Right Front Wheel Speed Sensor Circuit Open

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

DTC C0040 26: Right Front Wheel Speed Sensor Circuit Signal Frequency Too Low

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Left Front Sensor Signal	C0035 02	C0035 04	C0035 01	C0035 0F, C0035 26
Right Front Sensor Signal	C0040 02	C0040 04	C0040 01	C0040 0F, C0040 26
Left Front Sensor Low Reference	C0035 02	C0035 04	C0035 01	C0035 0F, C0035 26
Right Front Sensor Low Reference	C0040 02	C0040 04	C0040 01	C0040 0F, C0040 26

Mechanical Conditions

Component	Condition	DTCs
Left Front Wheel Speed Sensor	•  Physical damage     •  Debris on the wheel speed sensor or the encoder ring     •  Loose or improperly mounted sensor     •  Loose or worn wheel bearing     •  Air gap between the wheel speed sensor and the encoder ring too large	C0040 0F
Right Front Wheel Speed Sensor	•  Physical damage     •  Debris on the wheel speed sensor or the encoder ring     •  Loose or improperly mounted sensor     •  Loose or worn wheel bearing     •  Air gap between the wheel speed sensor and the encoder ring too large	C0040 0F

Circuit/System Description

The wheel speed sensor receives voltage from the electronic brake control module (EBCM) and provides a AC signal back to the module. As the wheel spins, the EBCM uses the frequency of the signal to calculate the wheel speed.

Conditions for Running the DTC

Conditions for Setting the DTC

Action Taken When the DTC Sets

Conditions for Clearing the DTC

Diagnostic Aids

If 2 or more wheel speed sensors are inoperative diagnose each wheel speed sensor individually.

C0035 0F or C0040 0F

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 13 km/h (8 mph) for at least 30 seconds.
3. 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

Ignition ON, 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 EBCM.
2. Ignition ON, test for less than 1 volt between the wheel speed sensor low reference circuit terminal of the appropriate sensor listed below and ground.

•	LF Sensor circuit terminal 16

•	RF Sensor circuit terminal 27

⇒	If greater than the specified range, test the low reference circuit for a short to voltage.

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

•	LF Sensor circuit terminal 15

•	RF Sensor circuit terminal 26

⇒	If greater than the specified range, test the signal circuit for a short to voltage.

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

•	LF Sensor circuit terminal 15

•	RF Sensor circuit terminal 26

⇒	If less than the specified value, test the signal circuit for a short to ground.

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

•	LF Sensor circuit terminal 16

•	RF Sensor circuit terminal 27

⇒	If less than the specified value, test the signal circuit for a short to ground.

6. Ignition OFF, disconnect the harness connector at the appropriate WSS.
7. Ignition OFF, test for less than 2 ohms between the appropriate signal circuit terminals listed below.

•	LF Sensor signal circuit terminal 15 at the EBCM harness connector, and terminal B at the WSS harness connector

•	RF Sensor signal circuit terminal 26 at the EBCM harness connector, and terminal B at the WSS harness connector

⇒	If greater than the specified range, test the signal circuit for an open or high resistance.

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

•	LF Sensor low reference circuit terminal 16 at the EBCM harness connector, and terminal A at the WSS harness connector

•	RF Sensor low reference circuit terminal 27 at the EBCM harness connector, and terminal A at the WSS harness connector

⇒	If greater than the specified range, test the low reference circuit for an open or high resistance.

9. If all circuits test normal, replace the appropriate wheel speed sensor. If the DTC resets replace the EBCM.

Component Testing

1. Disconnect the wheel speed sensor connector.
2. Ignition OFF, measure for 700-10,000 ohms across the wheel speed sensor.

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

3. Spin the wheel, with a scan tool measure the AC voltage across the wheel speed sensor for 100 mv AC or greater.

⇒	If the AC voltage is less than the specified value, replace the faulty wheel speed sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.