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

DTC C0035 00: Left Front Wheel Speed Sensor Circuit
DTC C0040 00: Right Front Wheel Speed Sensor Circuit
DTC C0045 00: Left Rear Wheel Speed Sensor Circuit
DTC C0050 00: Right Rear Wheel Speed Sensor Circuit

### Diagnostic Fault Information

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

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

C0035 00

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 00

Left Rear 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

C0045 00

Right Rear 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

C0050 00

### Circuit/System Description

The wheel speed sensor receives ignition voltage from the electronic brake control module (EBCM) and provides an output signal to the EBCM. As the wheel spins, the wheel speed sensor sends 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

• | Ignition ON.

• | The brake pedal is not pressed.

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

### Conditions for Setting the DTC

#### C0035-C0050 00

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

### Action Taken When the DTC Sets

• | The EBCM disables the antilock brake system (ABS) for the duration of the ignition cycle.

• | A DIC message and/or a warning indicator may be displayed.

### Conditions for Clearing the DTC

• | The condition for setting the DTC is no longer present.

• | The EBCM clears the history DTC when a current DTC is not detected in 50 consecutive drive cycles.

• | ECE 13, the ABS indicator will remain on until a vehicle speed of 13 km/h (8 mph) or greater is achieved.

### 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. Also rotate steering wheel from stop to stop for intermittent condition caused from open or chaffing of the front wheel speed sensor harness.
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

• | 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 45

• | RF Sensor circuit terminal 34

• | LR Sensor circuit terminal 36

• | RR Sensor circuit terminal 43

⇒ | If greater than the specified range, test the12 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 46

• | RF Sensor circuit terminal 33

• | LR Sensor circuit terminal 37

• | RR Sensor circuit terminal 42

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

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

• | LF Sensor circuit terminal 45

• | RF Sensor circuit terminal 34

• | LR Sensor circuit terminal 36

• | RR Sensor circuit terminal 43

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

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

• | LF Sensor circuit terminal 46

• | RF Sensor circuit terminal 33

• | LR Sensor circuit terminal 37

• | RR Sensor circuit terminal 42

⇒ | 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 appropriate12 volt reference circuit terminals listed below.

• | LF Sensor circuit terminal 45 at the EBCM harness connector and terminal B at the WSS harness connector.

• | RF Sensor circuit terminal 34 at the EBCM harness connector and terminal B at the WSS harness connector.

• | LR Sensor circuit terminal 36 at the EBCM harness connector and terminal B at the WSS harness connector.

• | RR Sensor circuit terminal 43 at the EBCM harness connector and terminal B 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 46 at the EBCM harness connector and terminal A at the WSS harness connector.

• | RF Sensor circuit terminal 33 at the EBCM harness connector and terminal A at the WSS harness connector.

• | LR Sensor circuit terminal 37 at the EBCM harness connector and terminal A at the WSS harness connector.

• | RR Sensor circuit terminal 42 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.

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 Speed Sensor Replacement

• | Rear Wheel Speed Sensor Replacement

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