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 CircuitDTC 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
DTC C1221 00: Left Front Wheel Speed Sensor Circuit (HP7)
DTC C1222 00: Right Front Wheel Speed Sensor Circuit (HP7)
DTC C1223 00: Left Rear Wheel Speed Sensor Circuit (HP7)
DTC C1224 00: Right Rear Wheel Speed Sensor Circuit (HP7)
DTC C1225 00: Left Front Wheel Speed Sensor Circuit Range/Performance (HP7)
DTC C1226 00: Right Front Wheel Speed Sensor Circuit Range/Performance (HP7)
DTC C1227 00: Left Rear Wheel Speed Sensor Circuit Range/Performance (HP7)
DTC C1228 00: Right Rear Wheel Speed Sensor Circuit Range/Performance (HP7)
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Left Front Sensor Signal | C0035 00, C1221 00 | C0035 00, C1221 00 | C0035 00, C1221 00 | C0035 0F, C0035 18, C1225 00 |
Left Front Sensor Low Reference | C0035 00, C1221 00 | C0035 00, C1221 00 | C0035 00, C1221 00 | C0035 0F, C0035 18, C1225 00 |
Right Front Sensor Signal | C0040 00, C1222 00 | C0040 00, C1222 00 | C0040 00, C1222 00 | C0040 0F, C0040 18, C1226 00 |
Right Front Sensor Low Reference | C0040 00, C1222 00 | C0040 00, C1222 00 | C0040 00, C1222 00 | C0040 0F, C0040 18, C1226 00 |
Left Rear Sensor Signal | C0045 00, C1223 00 | C0045 00, C1223 00 | C0045 00, C1223 00 | C0045 0F, C0045 18, C1227 00 |
Left Rear Sensor Low Reference | C0045 00, C1223 00 | C0045 00, C1223 00 | C0045 00, C1223 00 | C0045 0F, C0045 18, C1227 00 |
Right Rear Sensor Signal | C0050 00, C1224 00 | C0050 00, C1224 00 | C0050 00, C1224 00 | C0050 0F, C0050 18, C1228 00 |
Right Rear Sensor Low Reference | C0050 00, C1224 00 | C0050 00, C1224 00 | C0050 00, C1224 00 | C0050 0F, C0050 18, C1228 00 |
Circuit/System Description
The wheel speed sensor receives B+ from the electronic brake control module (EBCM). As the wheel spins, the wheel speed sensor sends the EBCM a DC square wave signal. The EBCM uses the frequency of the square wave signal to calculate the wheel speed.
With RPO (HP7), when a wheel speed sensor fault is detected, the EBCM sends a serial data message to the engine control module (ECM), and the ECM sets a DTC and illuminates the MIL.
Conditions for Running the DTC
C0035 00-C0050 00 or C1221 00-C1224 00
Ignition ON.
C0035 0F-C0050 0F or C1225 00-C1228 00
| • | 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. |
| • | The brake pedal is not pressed. |
| • | No other wheel speed circuit DTCs are set. |
| • | At least two other wheel speeds are not 0 km/h. |
Conditions for Setting the DTC
C0035 00-C0050 00 or C1221 00-C1224 00
The EBCM detects an open or a short to ground or a short to B+ on the wheel speed sensor signal circuits.
C0035 0F-C0050 0F or C1221 00-C1228 00
If the EBCM detects a change in wheel speed that exceeds 20 km/h (12 mph) between two 10-millisecond wheel speed samples. If the condition occurs 3 times in 200 milliseconds, the code is set.
C0035 18-C0050 18 or C1221 00-C1224 00
The code is set when the following conditions exist:
| • | 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 other. |
Action Taken When the DTC Sets
If equipped, the following actions occur:
| • | The EBCM disables the ABS/TCS for the duration of the ignition cycle. |
| • | The EBCM sends a serial data message to illuminate the appropriate indicator and message. |
Diagnostic Aids
C0035 18-C0050 18
Under the following conditions, 2 Wheel Speed Sensor Input is 0 and DTCs are set:
| • | The 2 suspect wheel speeds equal zero for 6 seconds. |
| • | The other wheel speeds are greater than 16 km/h (10 mph). |
| • | The other wheel speeds are within 11 km/h (7 mph) of each other. |
Diagnose each wheel speed sensor individually.
C0035-C0050 18, 0F, 00
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 40 km/h (25 mph) for at least 30 seconds.
- If the DTC returns, replace the suspected wheel speed sensor or repair the wheel speed sensor wiring.
- Rinse the area thoroughly when completed.
Reference Information
Schematic Reference
Antilock Brake System Schematics
Connector End View Reference
Description and Operation
Electrical Information Reference
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
Important: It is recommended that Component Testing is performed before Circuit Testing when diagnosing wheel speed sensors.
- Ignition OFF, disconnect the harness connector at the EBCM.
- Ignition ON, test for less than 1 volt between the low reference circuit terminal of the appropriate sensor listed below and ground.
- Test for less than 1 volt between the signal circuit terminal of the appropriate sensor listed below and ground.
- Ignition OFF, test for infinite resistance between the low reference terminal of the appropriate sensor listed below and ground.
- Test for infinite resistance between the following signal circuit terminal of the appropriate sensor listed below and ground.
- Ignition OFF, disconnect the harness connector at the appropriate wheel speed sensor.
- Test for less than 2 ohms between the appropriate low reference circuit terminals listed below:
- Test for less than 2 ohms between the appropriate signal circuit terminals listed below:
- If all circuits test normal, replace the EBCM.
| • | LF Sensor circuit terminal 45 |
| • | RF Sensor circuit terminal 34 |
| • | LR Sensor circuit terminal 36 |
| • | RR Sensor circuit terminal 43 |
| ⇒ | If greater than the specified value, test the low reference circuit for a short to voltage. If the circuit tests normal, test or replace the wheel speed sensor. |
| • | LF Sensor circuit terminal 46 |
| • | RF Sensor circuit terminal 33 |
| • | LR Sensor circuit terminal 37 |
| • | RR Sensor circuit terminal 42 |
| ⇒ | If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, test or replace the wheel speed sensor. |
| • | LF Sensor circuit terminal 45 |
| • | RF Sensor circuit terminal 34 |
| • | LR Sensor circuit terminal 36 |
| • | RR Sensor circuit terminal 43 |
| ⇒ | 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. |
| • | LF Sensor circuit terminal 46 |
| • | RF Sensor circuit terminal 33 |
| • | LR Sensor circuit terminal 37 |
| • | RR Sensor circuit terminal 42 |
| ⇒ | 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. |
| • | LF sensor circuit terminal 45 at the EBCM harness connector and terminal B at the WSS harness connector |
| • | RF sensor circuit terminal 34 at the EBCM harness connector and terminal B at the WSS harness connector |
| • | LR sensor circuit terminal 36 at the EBCM harness connector and terminal B at the WSS harness connector |
| • | RR sensor circuit terminal 43 at the EBCM harness connector and terminal B at the WSS harness connector |
| ⇒ | If greater than the specified value, test the low reference circuit for an open or high resistance. If the circuit tests normal, test or replace the wheel speed sensor. |
| • | LF sensor circuit terminal 46 at the EBCM harness connector and terminal A at the WSS harness connector |
| • | RF sensor circuit terminal 33 at the EBCM harness connector and terminal A at the WSS harness connector |
| • | LR sensor circuit terminal 37 at the EBCM harness connector and terminal A at the WSS harness connector |
| • | RR sensor circuit terminal 42 at the EBCM harness connector and terminal A at the WSS harness connector |
| ⇒ | If greater than the specified value, test the signal circuit for an open or high resistance. If the circuit tests normal, test or replace the wheel speed sensor. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for EBCM replacement, setup, and programming |
