Diagnostic Instructions
DTC Descriptors
DTC C0035 01: Left Front Wheel Speed Sensor Circuit Short to Battery
DTC C0035 02: Left Front Wheel Speed Sensor Circuit Short to Ground
DTC C0035 04: Left Front Wheel Speed Sensor Circuit Open
DTC C0035 0F: Left Front Wheel Speed Sensor Circuit Signal Erratic
DTC C0035 26: Left Front Wheel Speed Sensor Circuit Signal Frequency Too Low
DTC C0040 01: Right Front Wheel Speed Sensor Circuit Short to Battery
DTC C0040 02: Right Front Wheel Speed Sensor Circuit Short to Ground
DTC C0040 04: Right Front Wheel Speed Sensor Circuit Open
DTC C0040 0F: Right Front Wheel Speed Sensor Circuit Signal Erratic
DTC C0040 26: Right Front Wheel Speed Sensor Circuit Signal Frequency Too Low
Diagnostic Fault Information
Circuit
| Short to Ground
| Open/High Resistance
| Short to Voltage
| Signal Performance
|
Left Front Sensor Signal
| C0035 02
| C0035 04
| C0035 01
| C0035 0F, C0035 26
|
Right Front Sensor Signal
| C0040 02
| C0040 04
| C0040 01
| C0040 0F, C0040 26
|
Left Front Sensor Low Reference
| C0035 02
| C0035 04
| C0035 01
| C0035 0F, C0035 26
|
Right Front Sensor Low Reference
| C0040 02
| C0040 04
| C0040 01
| C0040 0F, C0040 26
|
Mechanical Conditions
Component
| Condition
| DTCs
|
Left Front Wheel Speed Sensor
|
• | Debris on the wheel speed sensor or the encoder ring |
• | Loose or improperly mounted sensor |
• | Loose or worn wheel bearing |
• | Air gap between the wheel speed sensor and the encoder ring too large |
| C0040 0F
|
Right Front Wheel Speed Sensor
|
• | Debris on the wheel speed sensor or the encoder ring |
• | Loose or improperly mounted sensor |
• | Loose or worn wheel bearing |
• | Air gap between the wheel speed sensor and the encoder ring too large |
| C0040 0F
|
Circuit/System Description
The wheel speed sensor receives voltage from the electronic brake control module (EBCM) and provides a AC signal back to the module. As the wheel spins, the EBCM uses the frequency of the signal to calculate the wheel speed.
Conditions for Running the DTC
• | Ignition voltage is greater than 10 volts. |
Conditions for Setting the DTC
• | An erratic signal output of the wheel speed sensor is detected. |
• | A short to voltage, 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. |
Action Taken When the DTC Sets
• | The EBCM disables the Antilock Brake System (ABS)/Traction Control System (TCS) for the duration of the ignition cycle. |
• | A DIC message and/or a warning indicator may be displayed. |
Conditions for Clearing the DTC
• | The condition for setting the DTC is no longer present. |
• | The EBCM clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles. |
Diagnostic Aids
If 2 or more wheel speed sensors are inoperative diagnose each wheel speed sensor individually.
C0035 0F or C0040 0F
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:
- 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).
- Test drive the vehicle over various road surfaces: bumps, turns, etc., above 13 km/h (8 mph) for at least 30 seconds.
- 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
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
- Ignition OFF, disconnect the harness connector at the EBCM.
- Ignition ON, test for less than 1 volt between the wheel speed sensor low reference circuit terminal of the appropriate sensor listed below and ground.
• | LF Sensor circuit terminal 16 |
• | RF Sensor circuit terminal 27 |
⇒ | If greater than the specified range, test the low reference circuit for a short to voltage. |
- Test for less than 1 volt between the signal circuit terminal of the appropriate sensor listed below and ground.
• | LF Sensor circuit terminal 15 |
• | RF Sensor circuit terminal 26 |
⇒ | If greater than the specified range, test the signal circuit for a short to voltage. |
- Ignition OFF, test for infinite resistance between the signal circuit terminal of the appropriate sensor listed below and ground.
• | LF Sensor circuit terminal 15 |
• | RF Sensor circuit terminal 26 |
⇒ | If less than the specified value, test the signal circuit for a short to ground. |
- Test for infinite resistance between the following low reference circuit terminal of the appropriate sensor listed below and ground.
• | LF Sensor circuit terminal 16 |
• | RF Sensor circuit terminal 27 |
⇒ | If less than the specified value, test the signal circuit for a short to ground. |
- Ignition OFF, disconnect the harness connector at the appropriate WSS.
- Ignition OFF, test for less than 2 ohms between the appropriate signal circuit terminals listed below.
• | LF Sensor signal circuit terminal 15 at the EBCM harness connector, and terminal B at the WSS harness connector |
• | RF Sensor signal circuit terminal 26 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. |
- Test for less than 2 ohms between the appropriate low reference circuit terminals listed below.
• | LF Sensor low reference circuit terminal 16 at the EBCM harness connector, and terminal A at the WSS harness connector |
• | RF Sensor low reference circuit terminal 27 at the EBCM harness connector, and terminal A at the WSS harness connector |
⇒ | If greater than the specified range, test the low reference circuit for an open or high resistance. |
- If all circuits test normal, replace the appropriate wheel speed sensor. If the DTC resets replace the EBCM.
Component Testing
- Disconnect the wheel speed sensor connector.
- Ignition OFF, measure for 700-10,000 ohms across the wheel speed sensor.
⇒ | If the resistance is not within the specified range, replace the faulty wheel speed sensor. |
- Spin the wheel, with a scan tool measure the AC voltage across the wheel speed sensor for 100 mv AC or greater.
⇒ | If the AC voltage is less than the specified value, replace the faulty wheel speed sensor. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.