GM Service Manual Online
For 1990-2009 cars only

DTC C0035-C0050 Without JL7

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

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

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

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

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 Wheel Speed Sensor Signal

C0035 00

C0035 00

--

C0035 0F, C0035 18

Left Front Wheel Speed Sensor Low Reference

--

--

C0035 00

C0035 0F, C0035 18

Right Front Wheel Speed Sensor Signal

C0040 00

C0040 00

--

C0040 0F, C0040 18

Right Front Wheel Speed Sensor Low Reference

--

--

C0040 00

C0040 0F, C0040 18

Left Rear Wheel Speed Sensor Signal

C0045 00

C0045 00

--

C0045 0F, C0045 18

Left Rear Wheel Speed Sensor Low Reference

--

--

C0045 00

C0045 0F, C0045 18

Right Rear Wheel Speed Sensor Signal

C0050 00

C0050 00

--

C0050 0F, C0050 18

Right Rear Wheel Speed Sensor Low Reference

--

--

C0050 00

C0050 0F, C0050 18

Circuit/System Description

As the wheel spins, the wheel speed sensor produces an alternating current (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 00-C0050 00

Ignition ON.

C0035 0F-C0050 0F

    • Ignition ON.
    • The brake pedal is not pressed.
    • A DTC is not set for the other wheel speed circuit on the same axle.

C0035 18-C0050 18

    • Ignition ON.
    • No other wheel speed circuit DTCs are set.
    • The brake pedal is not pressed.
    • Two or three other wheel speeds are greater than 0 km/h.

Conditions for Setting the DTC

C0035 00-C0050 00

    • An open or a short to ground is detected on the wheel speed sensor signal circuit by the EBCM.
    • A short to voltage is detected on the wheel speed sensor signal circuit by the EBCM.

C0035 0F-C0050 0F

    • The EBCM detects a change in wheel speed that exceeds 20 km/h (12 mph) between two 10 millisecond wheel speed samples.
    • The condition occurs 3 times in 200 milliseconds.

C0035 18-C0050 18

    • One wheel speed is 0 km/h.
    • The remaining wheel speeds are greater than 8 km/h (5 mph).
    • The difference between the remaining wheel speeds is less than 11 km/h (7 mph) from each sensor.

Actions Taken when the DTC Sets

If equipped, the following actions occur:

    • The EBCM disables the antilock brake system (ABS) and the traction control system (TCS) for the duration of the ignition cycle.
    • The ABS indicator turns ON.
    • The traction control off indicator turns ON.

Conditions for Clearing the DTC

    • A current DTC clears when the diagnostic runs and passes.
    • A history DTC clears after 100 consecutive ignition 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

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 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 low reference circuit terminals of the appropriate sensor listed below and ground .
  3. • LF Sensor circuit terminal A2
    • RF Sensor circuit terminal A4
    • LR Sensor circuit terminal A6
    • RR Sensor circuit terminal A8
    If greater than the specified range, test the low reference circuit for a short to voltage. If the circuit tests normal, replace the wheel speed sensor
  4. Test for less than 1 volt between the signal circuit terminals of the appropriate sensor listed below and ground.
  5. • LF Sensor circuit terminal A1
    • RF Sensor circuit terminal A3
    • LR Sensor circuit terminal A5
    • RR Sensor circuit terminal A7
    If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the wheel speed sensor.
  6. Ignition OFF, test for infinite resistance between the low reference terminals of the appropriate sensor listed below and ground.
  7. • LF Sensor circuit terminal A2
    • RF Sensor circuit terminal A4
    • LR Sensor circuit terminal A6
    • RR Sensor circuit terminal A8
    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.
  8. Test for infinite resistance between the following signal circuit terminals of the appropriate sensor listed below and ground.
  9. • LF Sensor circuit terminal A1
    • RF Sensor circuit terminal A3
    • LR Sensor circuit terminal A5
    • RR Sensor circuit terminal A7
    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.
  10. Test for less than 2 ohms between the appropriate signal circuit terminals listed below.
  11. • LF Sensor circuit terminals A1 at the EBCM harness connector, and terminal A at the WSS harness connector
    • RF Sensor circuit terminals A3 at the EBCM harness connector, and terminal A at the WSS harness connector
    • LR Sensor circuit terminals A5 at the EBCM harness connector, and terminal A at the WSS harness connector
    • RR Sensor circuit terminals A7 at the EBCM harness connector, and terminal A at the WSS harness connector
    If greater than the specified range, test the signal circuit for an open or high resistance. If the circuit tests normal, test or replace the wheel speed sensor.
  12. Test for less than 2 ohms between the appropriate signal circuit terminals listed below.
  13. • LF Sensor circuit terminals A2 at the EBCM harness connector, and terminal B at the WSS harness connector
    • RF Sensor circuit terminals A4 at the EBCM harness connector, and terminal B at the WSS harness connector
    • LR Sensor circuit terminals A6 at the EBCM harness connector, and terminal B at the WSS harness connector
    • RR Sensor circuit terminals A8 at the EBCM harness connector, and terminal B at the WSS harness connector
    If greater than the specified range, test the signal circuit for an open or high resistance. If the circuit tests normal, test or replace the wheel speed sensor.
  14. If all circuits test normal, replace the EBCM.

Component Testing

  1. Ignition OFF, disconnect the harness connector at the appropriate wheel speed sensor.
  2. Test for 850-1350 ohms between terminal A and terminal B of the wheel speed sensor.
  3. If not within the specified range, replace the wheel speed sensor.
  4. Test for greater than 100 mV AC voltage between terminal A and terminal B of the wheel speed sensor, when spinning the wheel.
  5. 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 Bearing and Hub Replacement
    •  Rear Wheel Bearing and Hub Replacement
    •  Control Module References for EBCM replacement, setup, and programming

DTC C0035-C0050 With JL7

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 02 : Left Front Wheel Speed Sensor Circuit Short to Ground

DTC C0035 05 : Left Front Wheel Speed Sensor Circuit Short to Battery or Open

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 02 : Right Front Wheel Speed Sensor Circuit Short to Ground

DTC C0040 05 : Right Front Wheel Speed Sensor Circuit Short to Battery or Open

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 02 : Left Rear Wheel Speed Sensor Circuit Short to Ground

DTC C0045 05 : Left Rear Wheel Speed Sensor Circuit Short to Battery or Open

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 02 : Right Rear Wheel Speed Sensor Circuit Short to Ground

DTC C0050 05 : Right Rear Wheel Speed Sensor Circuit Short to Battery or Open

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 Wheel Speed Sensor Signal

C0035 02

C0035 05

C0035 05

C0035 0F, C0035 18

Left Front Wheel Speed Sensor Low Reference

C0035 02

C0035 05

C0035 05

C0035 0F, C0035 18

Right Front Wheel Speed Sensor Signal

C0040 02

C0040 05

C0040 05

C0040 0F, C0040 18

Right Front Wheel Speed Sensor Low Reference

C0040 02

C0040 05

C0040 05

C0040 0F, C0040 18

Left Rear Wheel Speed Sensor Signal

C0045 02

C0045 05

C0045 05

C0045 0F, C0045 18

Left Rear Wheel Speed Sensor Low Reference

C0045 02

C0045 05

C0045 05

C0045 0F, C0045 18

Right Rear Wheel Speed Sensor Signal

C0050 02

C0050 05

C0050 05

C0050 0F, C0050 18

Right Rear Wheel Speed Sensor Low Reference

C0050 02

C0050 05

C0050 05

C0050 0F, C0050 18

Circuit/System Description

As the wheel spins, the wheel speed sensor produces an alternating current (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 02 and 05-C0050 02 and 05

Ignition ON.

C0035 0F-C0050 0F

    • Ignition ON.
    • The brake pedal is not pressed.
    • A DTC is not set for the other wheel speed circuit on the same axle.

C0035 18-C0050 18

    • Ignition ON.
    • No other wheel speed circuit DTCs are set.
    • The brake pedal is not pressed.
    • Two or three other wheel speeds are greater than 0 km/h.

Conditions for Setting the DTC

C0035 02-C0050 02

    • A short to ground is detected on the wheel speed sensor circuits.
    • Wheel speed sensor power supply is less than 7.6 volts.

C0035 05-C0050 05

A short to voltage or an open is detected on the wheel speed sensor circuits.

C0035 0F and 18-C0050 0F and 18

    • An erratic signal output of the wheel speed sensor is detected 3 times in 200 milliseconds.
    • The EBCM detects a change in wheel speed that exceeds 20 km/h (12 mph) between two 10 millisecond wheel speed samples. This is detected 3 times in 200 milliseconds.
    • A missing wheel speed sensor signal.

Actions Taken when the DTC Sets

If equipped, the following actions occur:

    • The EBCM disables the antilock brake system (ABS) and the traction control system (TCS) for the duration of the ignition cycle.
    • The ABS indicator turns ON.
    • The traction control off indicator turns ON.

Conditions for Clearing the DTC

    • A current DTC clears when the diagnostic runs and passes.
    • A history DTC clears after 100 consecutive ignition 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

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 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 low reference circuit terminals of the appropriate sensor listed below and ground.
  3. • LF Sensor circuit terminal 28
    • RF Sensor circuit terminal 17
    • LR Sensor circuit terminal 4
    • RR Sensor circuit terminal 3
    If greater than the specified range, test the low reference circuit for a short to voltage. If the circuit tests normal, replace the EBCM.
  4. Test for less than 1 volt between the signal circuit terminals of the appropriate sensor listed below and ground.
  5. • LF Sensor circuit terminal 27
    • RF Sensor circuit terminal 30
    • LR Sensor circuit terminal 16
    • RR Sensor circuit terminal 15
    If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the EBCM.
  6. Ignition OFF, test for infinite resistance between the low reference terminals of the appropriate sensor listed below and ground.
  7. • LF Sensor circuit terminal 28
    • RF Sensor circuit terminal 17
    • LR Sensor circuit terminal 4
    • RR Sensor circuit terminal 3
    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.
  8. Test for infinite resistance between the following signal circuit terminals of the appropriate sensor listed below and ground.
  9. • LF Sensor circuit terminal 27
    • RF Sensor circuit terminal 30
    • LR Sensor circuit terminal 16
    • RR Sensor circuit terminal 15
    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.
  10. Ignition OFF, disconnect the harness connector at the wheel speed sensor.
  11. Test for less than 2 ohms between the appropriate signal circuit terminals listed below.
  12. • LF Sensor circuit terminals 28 at the EBCM harness connector, and terminal A at the WSS harness connector
    • RF Sensor circuit terminals 17 at the EBCM harness connector, and terminal A at the WSS harness connector
    • LR Sensor circuit terminals 4 at the EBCM harness connector, and terminal A at the WSS harness connector
    • RR Sensor circuit terminals 3 at the EBCM harness connector, and terminal A at the WSS harness connector
    If greater than the specified range, test the signal circuit for an open or high resistance. If the circuit tests normal, test or replace the wheel speed sensor.
  13. Test for less than 2 ohms between the appropriate low reference circuit terminals listed below.
  14. • LF Sensor circuit terminals 27 at the EBCM harness connector, and terminal B at the WSS harness connector
    • RF Sensor circuit terminals 30 at the EBCM harness connector, and terminal B at the WSS harness connector
    • LR Sensor circuit terminals 16 at the EBCM harness connector, and terminal B at the WSS harness connector
    • RR Sensor circuit terminals 15 at the EBCM harness connector, and terminal B at the WSS harness connector
    If greater than the specified range, test the low reference circuit for an open or high resistance. If the circuit tests normal, test or replace the wheel speed sensor.
  15. 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