C0035
DTC C0035
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
DTC Descriptors
DTC C0035
- Left Front Wheel Speed Sensor Circuit or Front Sensor Supply Voltage Circuit
Diagnostic Fault Information
Circuit/System Description
The electronic brake control module (EBCM) provides a common supply voltage to each digital front wheel speed sensor. As the front wheels spin, each wheel speed sensor produces a digital square wave signal. The EBCM uses the frequency of the wheel speed sensor signal to determine wheel speed.
Conditions for Running the DTC
* The ignition is ON.
* The vehicle achieves a speed greater than 40 km/h (25 mph).
Conditions for Setting the DTC
Any of the following conditions may cause this DTC to set.
* The EBCM detects an open or shorted wheel speed sensor for 200 milliseconds.
* The EBCM detects a missing wheel speed sensor signal for one second. If more than one absent wheel speed sensor signal is detected, the condition must be present for 20 seconds to set DTCs.
* The EBCM detects an erratic wheel speed sensor signal for 40 continuous or cumulative milliseconds.
* The supply voltage to the front wheel speed sensors is detected as being at least 5 volts less than the monitored ignition voltage.
Action Taken When the DTC Sets
* The EBCM disables the Antilock Brake System (ABS).
* The EBCM disables the TCS.
* The EBCM disables dynamic rear proportion (DRP), if all wheel speed inputs have failed.
* The ABS indicator turns ON.
* The ABS fault message is displayed.
* The traction fault message is displayed.
* The brake warning indicator turns ON, if DRP is disabled.
* The brakes message is displayed.
* An ECE 13 response occurs. Refer to ABS Description and Operation (Description and Operation) for a 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.
Diagnostic Aids
Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. Refer to Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics), Connector Repairs (Component Tests and General Diagnostics), Testing for Electrical Intermittents (Component Tests and General Diagnostics) and Wiring Repairs (Component Tests and General Diagnostics) .
If the customers concern is that the ABS indicator is on only during humid conditions, such as rain, snow, or vehicle wash, thoroughly inspect the wheel speed sensor circuits for signs of water intrusion. Use the following procedure in order to help isolate the problem area:
1. Spray the suspected area with a 5 percent salt water solution.
2. Drive the vehicle at a speed greater than 19 km/h (12 mph) for at least 30 seconds.
Repair or replace the suspect harness, if the DTC sets.
Reference Information
Schematic Reference
Antilock Brake System Schematics ([1][2]Antilock Brakes / Traction Control Systems)
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 (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
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 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
Important: It is recommended that Component Testing is performed before Circuit Testing when diagnosing wheel speed sensors because the module will default and does not supply voltage to the sensor when the DTC is set.
Performing Circuit Testing with EBCM connector disconnected and key on will cause U codes to set. Clear DTCs after performing the test.
1. Ignition OFF, disconnect the harness connector at the suspect wheel speed sensor.
2. Ignition ON, test for 0 volts between the sensor signal circuit terminal 2 and ground.
• If not the specified value, test the sensor signal circuit for a short to voltage. If the circuit tests normal, replace the EBCM.
3. Disconnect the harness connector at the EBCM.
4. Test for infinite resistance between the sensor signal circuit terminal 2 and ground.
• If not the specified value, test the sensor signal circuit for a short to ground.
5. Test for less than 1 ohm of resistance between the sensor signal circuit terminals of the appropriate sensor listed below.
* LF sensor terminals 2 and 26
* RF sensor terminals 2 and 11
• If greater than the specified range, test the low reference circuit for an open/high resistance.
6. Test for infinite resistance between the supply voltage circuit and ground.
• If not the specified value, test the supply voltage circuit for a short to ground.
7. Test for less than 1 ohm of resistance between the signal circuit terminals.
* LF sensor terminals 1 and 18
* RF sensor terminals 1 and 12
• If not within the specified range, test the supply voltage circuit for an open/high resistance.
8. 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 12 volt test lamp between B+ and the wheel speed sensor supply voltage circuit terminal 1.
3. Test for 4-8 mA on the low reading between the sensor signal circuit 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 sensor signal circuit 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 (Verification Tests) after completing the diagnostic procedure.
* Front Wheel Speed Sensor Replacement (2WD) ()Front Wheel Speed Sensor Replacement (4WD) (Service and Repair)
* Control Module References (Programming and Relearning) for EBCM replacement, setup, and programming