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 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

As the wheel spins, the wheel speed sensor produces an AC signal. The electronic brake control module (EBCM) uses the frequency of the AC signal to calculate the wheel speed.

### Conditions for Running the DTC

#### C0035-C0050 00

• | The ignition is ON.

• | Ignition voltage is greater than 9.5 volts.

#### C0035-C0050 0F

• | The ignition is ON.

• | Ignition voltage is greater than 9.5 volts.

• | The brake pedal is not pressed.

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

#### C0035-C0050 18

• | The ignition is ON.

• | Ignition voltage is greater than 9.5 volts.

• | The brake pedal is not pressed.

• | No other wheel speed circuit DTCs are set.

• | At least two other wheel speeds are not 0 km/h.

### Conditions for Setting the DTC

#### C0035-C0050 00

• | An open is detected on the wheel speed sensor signal circuit.

• | A short to ground is detected on the wheel speed sensor signal circuit.

• | A short to voltage is detected on the wheel speed sensor signal circuit.

#### C0035-C0050 0F

The EBCM detects a rapid variation in the wheel speed. The wheel speed changes by 20 km/h (12 mph) or more in 0.01 second. The change must occur 3 times with no more than 0.2 seconds between occurrences.

#### C0035-C0050 18

• | One wheel speed is 2 km/h (1.2 mph).

• | The remaining wheel speeds are greater than 10 km/h (6.2 mph).

• | The difference between the remaining wheel speeds is less than 8 km/h (5 mph) from each other for 180 seconds.

OR

• | The 2 wheel speed sensor inputs are 0 and DTCs are set.

• | The 2 suspect wheel speeds equal zero for 6 seconds.

• | The other wheel speeds are greater than 15 km/h (10 mph).

• | The other wheel speeds are within 11 km/h (7 mph) of each other.

### Action Taken When the DTC Sets

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

• | The dynamic rear proportion (DRP) does not function optimally with multiple wheel speed faults.

• | The ABS indicator turns ON.

• | The engine traction system (ETS) indicator turns ON.

• | An ECE response may occur. Refer to ABS Description and Operation for complete description of ECE 13.

### Conditions for Clearing the DTC

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

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

• | The ABS indicator will remain on until a vehicle speed of 13 Km/h (8 mph) or greater is achieved, unless the Scan has cleared codes.

### 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. 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

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 15 km/h (10 mph).

### Circuit/System Testing

It is recommended 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 0 volts between the low reference circuit terminals 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 not the specified value, test the low reference circuit for a short to voltage. If the circuit tests normal, replace the EBCM.

3. Test for 0 volts between the signal circuit terminals 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 not the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the EBCM.

4. Ignition OFF, test for infinite resistance between the low reference terminals 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 not the specified value, test the low reference circuit for a short to ground. If the circuit tests normal, replace the EBCM.

5. Test for infinite resistance between the following signal circuit terminals 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 not the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the EBCM.

6. Test for 850-1350 ohms between the wheel speed sensor circuit terminals of the appropriate sensor listed below.

• | LF Sensor circuit terminals 8 and 9

• | RF Sensor circuit terminals 5 and 6

• | LR Sensor circuit terminals 2 and 3

• | RR Sensor circuit terminals 11 and 12

⇒ | If not within the specified range, test the low reference and signal circuits for an open/high resistance. If the circuit tests normal, replace the wheel speed sensor.

7. If all circuits test normal, 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