Antilock Brake System
DTC C0035-C0050
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
DTC Descriptor
DTC C0035 00
- Left Front Wheel Speed Sensor Circuit Malfunction
DTC C0035 5A
- Left Front Wheel Speed Sensor Circuit Not Plausible
DTC C0040 00
- Right Front Wheel Speed Sensor Circuit Malfunction
DTC C0040 5A
- Right Front Wheel Speed Sensor Circuit Not Plausible
DTC C0045 00
- Left Rear Wheel Speed Sensor Circuit Malfunction
DTC C0045 5A
- Left Rear Wheel Speed Sensor Circuit Not Plausible
DTC C0050 00
- Right Rear Wheel Speed Sensor Circuit Malfunction
DTC C0050 5A
- Right Rear Wheel Speed Sensor Circuit Not Plausible
Diagnostic Fault Information
Circuit/System Description
The wheel speeds are detected by active wheel speed sensors and encoder rings. The encoder ring consists of permanent magnets. Each wheel speed sensor receives ignition voltage from the electronic brake control module (EBCM) and provides an alternating current square wave signal to the Electronic Brake Control Module (EBCM). 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 5A - C0050 5A
* Ignition ON
* Vehicle speed is greater than 10 km/h (7 MPH)
Conditions for Setting the DTC
C0035 00 - C0050 00
* A short to voltage, short to ground, or open/high resistance on the wheel speed sensor ignition voltage circuit is detected for 0.2 s.
* A short to voltage, short to ground, or open/high resistance on the wheel speed sensor signal circuit is detected for 0.2 s.
* A short circuit on the wheel speed sensor ignition voltage and signal circuit is detected.
C0035 5A - C0050 5A
* Difference between fastest and slowest wheel speed is greater than 5% for 20 s.
* No wheel speed signal for 1 s.
* An invalid wheel speed sensor signal is detected for 10 s.
Action Taken When the DTC Sets
* The EBCM disables the ABS, traction control, and stability control for the duration of the ignition cycle.
* The ABS indicator turns ON.
* The traction control/stability control-active indicator turns ON.
Conditions for Clearing the DTC
* A current DTC clears when the diagnostic runs and passes.
* The EBCM will turn OFF the indicators and enable the system functions in the next ignition cycle after driving at a speed of greater than 15 km/h (9 MPH).
Diagnostic Aids
* Do not use a magnet to clean the encoder ring.
* 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% 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 s.
3. Rinse the area thoroughly when completed.
Reference Information
Schematic Reference
Antilock Brake System Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
ABS Description and Operation (Description and Operation)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
Ignition ON, observe the scan tool Wheel Speed Sensor parameters. 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 K17 Electronic Brake Control Module (EBCM).
2. Ignition ON, test for less than 1 V between the ignition voltage circuit terminal of the appropriate sensor listed below and ground.
* Left front wheel speed sensor circuit terminal 21
* Right front wheel speed sensor circuit terminal 18
* Left rear wheel speed sensor circuit terminal 33
* Right rear wheel speed sensor circuit terminal 19
• If greater than the specified range, test the ignition voltage circuit for a short to voltage.
3. Test for less than 1 V between the signal circuit terminal of the appropriate sensor listed below and ground.
* Left front wheel speed sensor circuit terminal 34
* Right front wheel speed sensor circuit terminal 6
* Left rear wheel speed sensor circuit terminal 20
* Right rear wheel speed sensor circuit terminal 31
• If greater than the specified range, test the signal circuit for a short to voltage.
4. Ignition OFF, test for infinite resistance between the ignition voltage terminal of the appropriate sensor listed below and ground.
* Left front wheel speed sensor circuit terminal 21
* Right front wheel speed sensor circuit terminal 18
* Left rear wheel speed sensor circuit terminal 33
* Right rear wheel speed sensor circuit terminal 19
• If less than the specified value, test the ignition voltage circuit for a short to ground.
5. Test for infinite resistance between the signal circuit terminal of the appropriate sensor listed below and ground.
* Left front wheel speed sensor circuit terminal 34
* Right front wheel speed sensor circuit terminal 6
* Left rear wheel speed sensor circuit terminal 20
* Right rear wheel speed sensor circuit terminal 31
• 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 B5 wheel speed sensor.
7. Ignition OFF, test for less than 2 ohm between the appropriate ignition voltage circuit terminals listed below.
* Left front wheel speed sensor ignition voltage circuit terminal 21 at the K17 Electronic Brake Control Module (EBCM) harness connector and terminal 1 at the wheel speed sensor harness connector
* Right front wheel speed sensor ignition voltage circuit terminal 18 at the K17 Electronic Brake Control Module (EBCM) harness connector and terminal 1 at the wheel speed sensor harness connector
* Left rear wheel speed sensor ignition voltage circuit terminal 33 at the K17 Electronic Brake Control Module (EBCM) harness connector and terminal 1 at the wheel speed sensor harness connector
* Right rear wheel speed sensor ignition voltage circuit terminal 19 at the K17 Electronic Brake Control Module (EBCM) harness connector and terminal 1 at the wheel speed sensor harness connector
• If greater than the specified value, test the ignition voltage circuit for an open or high resistance.
8. Test for less than 2 ohm between the appropriate signal circuit terminals listed below.
* Left front wheel speed sensor signal circuit terminal 34 at the K17 Electronic Brake Control Module (EBCM) harness connector and terminal 2 at the wheel speed sensor harness connector
* Right front wheel speed sensor signal circuit terminal 6 at the K17 Electronic Brake Control Module (EBCM) harness connector and terminal 2 at the wheel speed sensor harness connector
* Left rear wheel speed sensor signal circuit terminal 20 at the K17 Electronic Brake Control Module (EBCM) harness connector and terminal 2 at the wheel speed sensor harness connector
* Right rear wheel speed sensor signal circuit terminal 31 at the K17 Electronic Brake Control Module (EBCM) harness connector and terminal 2 at the wheel speed sensor 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 B5 wheel speed sensor. If the DTC resets, replace the K17 EBCM.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) 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 (Programming and Relearning) for EBCM replacement, programming and setup