C0045
DTC C0035-C0050
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 C0035 5A
- Left Front Wheel Speed Sensor Circuit Erratic Signal
DTC C0040 00
- Right Front Wheel Speed Sensor Circuit
DTC C0040 5A
- Right Front Wheel Speed Sensor Circuit Erratic Signal
DTC C0045 00
- Left Rear Wheel Speed Sensor Circuit
DTC C0045 5A
- Left Rear Wheel Speed Sensor Circuit Erratic Signal
DTC C0050 00
- Right Rear Wheel Speed Sensor Circuit
DTC C0050 5A
- Right Rear Wheel Speed Sensor Circuit Erratic Signal
Diagnostic Fault Information
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
* The ignition is ON.
* Ignition voltage is greater than 9.5 volts.
C0035 5A - C0050 5A
* 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 sensor on the same axle.
Conditions for Setting the DTC
C0035 00 - C0050 00
* A short to ground, open/high resistance is detected on the wheel speed sensor signal circuit.
* A short to voltage, short to ground or an open/high resistance is detected on the low reference circuit.
* Wheel speed sensor power supply is less than 7.6 volts.
* A missing wheel speed sensor signal
C0035 5A - C0050 5A
An erratic signal output of the wheel speed sensor is detected.
Action Taken When the DTC Sets
C0035 00 and 5A - C0050 00 and 5A
* The EBCM disables the antilock brake system (ABS)/traction control system (TCS) and VSES for the duration of the ignition cycle.
* The ABS indicator illuminates.
* The Traction Control indicator illuminates.
* The driver information center (DIC) displays the Service Stability System message.
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.
Diagnostic Aids
* Inspect the back of the wheel bearing on the encoder surface for metal debris that could cause an erratic reading with the sensor. Do not use a magnet to clean the debris, or damage to the encoder ring may occur.
* If 2 or more wheel speed sensors are inoperative diagnose each wheel speed sensor individually.
* An ECE 13 response may be required, after repairs are made, and DTCs are cleared, operate the vehicle at speeds greater than 15 km/h (10 mph) to complete the self test, and the EBCM will turn off the ABS indicator.
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 ([1][2]Antilock Brakes / Traction Control Systems)
Connector End View Reference
Component Connector End Views
Description and Operation
ABS Description and Operation (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
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 less than 1 volt between the low reference circuit terminals of the appropriate sensor listed below and ground .
* LF Sensor circuit terminal 34
* RF Sensor circuit terminal 6
* LR Sensor circuit terminal 20
* RR Sensor circuit terminal 31
• If greater than the specified value, test the low reference circuit for a short to voltage. If the circuit tests normal, replace the EBCM.
3. Test for less than 1 volt between the signal circuit terminals of the appropriate sensor listed below and ground.
* LF Sensor circuit terminal 21
* RF Sensor circuit terminal 18
* LR Sensor circuit terminal 33
* RR Sensor circuit terminal 19
• If greater than 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 34
* RF Sensor circuit terminal 6
* LR Sensor circuit terminal 20
* RR Sensor circuit terminal 31
• If less than the specified value, test the low reference circuit for a short to ground. If the circuit tests normal, test or replace the wheel speed sensor.
5. Test for infinite resistance between the following signal circuit terminals of the appropriate sensor listed below and ground.
* LF Sensor circuit terminal 21
* RF Sensor circuit terminal 18
* LR Sensor circuit terminal 33
* RR Sensor circuit terminal 19
• If less than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, test or replace the wheel speed sensor.
6. If all circuits test normal, replace the EBCM.
Component Testing
1. Ignition OFF, disconnect the harness connector at the wheel speed sensor.
2. Connect a test lamp between B+ and the wheel speed sensor signal circuit terminal 1.
3. Test for 4-8 mA on the low reading between the low reference terminal 2 and ground when spinning the wheel very slow.
• If not within the specified range, replace the wheel speed sensor.
4. Test for 12-16 mA on the high reading between the low reference terminal 2 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.
* Front Wheel Speed Sensor Replacement (Front Wheel Speed Sensor Replacement)
* Rear Wheel Speed Sensor Replacement (Rear Wheel Speed Sensor Replacement)
* Control Module References for EBCM replacement, setup, and programming