For 1990-2009 cars

### 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 Descriptor

C0035 00: Left Front Wheel Speed Sensor Circuit
C0035 08: Left Front Wheel Speed Sensor Circuit No Signal
C0035 0A: Left Front Wheel Speed Sensor Circuit Rate of Change Below Threshold
C0035 0F: Left Front Wheel Speed Sensor Circuit Erratic
C0040 00: Right Front Wheel Speed Sensor Circuit
C0040 08: Right Front Wheel Speed Sensor Circuit No Signal
C0040 0A: Right Front Wheel Speed Sensor Circuit Rate of Change Below Threshold
C0040 0F: Right Front Wheel Speed Sensor Circuit Erratic
C0045 00: Left Rear Wheel Speed Sensor Circuit
C0045 08: Left Rear Wheel Speed Sensor Circuit No Signal
C0045 0A: Left Rear Wheel Speed Sensor Circuit Rate of Change Below Threshold
C0045 0F: Left Rear Wheel Speed Sensor Circuit Erratic
C0050 00: Right Rear Wheel Speed Sensor Circuit
C0050 08: Right Rear Wheel Speed Sensor Circuit No Signal
C0050 0A: Right Rear Wheel Speed Sensor Circuit Rate of Change Below Threshold
C0050 0F: Right Rear Wheel Speed Sensor Circuit Erratic

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Left Front Sensor 12 Volt Reference | C0035 00 | C0035 08 | C0035 00 | C0035 0A, 0F, 08
Left Front Sensor Signal | C0035 00 | C0035 08 | C0035 00 | C0035 0A, 0F, 08
Right Front Sensor 12 Volt Reference | C0040 00 | C0040 00 | C0040 00 | C0040 0A 0F, 08
Right Front Sensor Signal | C0040 00 | C0040 00 | C0040 00 | C0040 0A 0F, 08
Left Rear Sensor 12 Volt Reference | C0045 00 | C0045 00 | C0045 00 | C0045 0A 0F, 08
Left Rear Sensor Signal | C0045 00 | C0045 00 | C0045 00 | C0045 0A 0F, 08
Right Rear Sensor 12 Volt Reference | C0050 00 | C0050 00 | C0050 00 | C0050 0A 0F, 08
Right Rear Sensor Signal | C0050 00 | C0050 00 | C0050 00 | C0050 0A 0F, 08

### Circuit/System Description

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

### Conditions for Running the DTC

#### C0035 00 - C0050 00

Ignition ON.

#### C0035 0A,0F,08 - C0050 0A,0F,08

• | Engine Running.

• | A DTC is not set for the other wheel speed sensor on the same axle.

### Conditions for Setting the DTC

#### C0035 00 - C0050 00

• | A short to ground, or an open/high resistance is detected on the wheel speed sensor voltage circuit.

• | A short to voltage, short to ground or an open/high resistance is detected on the signal circuit.

#### C0035 0A,0F - C0050 0A,0F

• | An erratic signal output of the wheel speed sensor is detected.

• | Wheel speed too high

#### C0035 0A,08 - C0050 0A,08

• | An erratic signal output of the wheel speed sensor is detected.

• | Wheel speed too low

### Action Taken When the DTC Sets

• | If equipped the EBCM disables the antilock brake system (ABS) / traction control system (TCS) / vehicle stability enhancement system (VSES) for the duration of the ignition cycle.

• | The EBCM sends a serial data message to illuminate the warning indicator/message.

### Conditions for Clearing the DTC

• | The condition for setting the DTC is no longer present and the vehicle is driven at a speed over 13 km/h (8 mph).

• | The EBCM clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

### Diagnostic Aids

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

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. 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

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### 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 12 volt reference circuit terminal of the appropriate sensor listed below and ground.

• | LF Sensor circuit terminal 9

• | RF Sensor circuit terminal 5

• | LR Sensor circuit terminal 3

• | RR Sensor circuit terminal 11

⇒ | If greater than the specified value, test the 12 volt 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 8

• | RF Sensor circuit terminal 6

• | LR Sensor circuit terminal 2

• | RR Sensor circuit terminal 12

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

4. Ignition OFF, test for infinite resistance between the 12 volt reference circuit terminal of the appropriate sensor listed below and ground.

• | LF Sensor circuit terminal 9

• | RF Sensor circuit terminal 5

• | LR Sensor circuit terminal 3

• | RR Sensor circuit terminal 11

⇒ | If less than the specified value, test the 12 volt reference circuit for a short to ground.

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

• | LF Sensor circuit terminal 8

• | RF Sensor circuit terminal 6

• | LR Sensor circuit terminal 2

• | RR Sensor circuit terminal 12

⇒ | 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 wheel speed sensor.
7. Test for less than 2 ohms between the appropriate 12 volt reference circuit terminals listed below:

• | LF sensor circuit terminal 9 at the EBCM harness connector and terminal 1 at the WSS harness connector

• | RF sensor circuit terminal 5 at the EBCM harness connector and terminal 1 at the WSS harness connector

• | LR sensor circuit terminal 3 at the EBCM harness connector and terminal 1 at the WSS harness connector

• | RR sensor circuit terminal 11 at the EBCM harness connector and terminal 1 at the WSS harness connector

⇒ | If greater than the specified value, test the 12 volt reference circuit for an open or high resistance.

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

• | LF sensor circuit terminal 8 at the EBCM harness connector and terminal 2 at the WSS harness connector

• | RF sensor circuit terminal 6 at the EBCM harness connector and terminal 2 at the WSS harness connector

• | LR sensor circuit terminal 2 at the EBCM harness connector and terminal 2 at the WSS harness connector

• | RR sensor circuit terminal 12 at the EBCM harness connector and terminal 2 at the WSS harness connector

⇒ | If greater than the specified value, test the signal 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.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Front Wheel Bearing and Hub Replacement

• | Rear Wheel Bearing and Hub Replacement

• | Control Module References for EBCM replacement, setup, and programming