C1224
DTC C0035-C0050 or C1221-C1228
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 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
DTC C1221
- Left Front Wheel Speed Sensor Circuit
DTC C1222
- Right Front Wheel Speed Sensor Circuit
DTC C1223
- Left Rear Wheel Speed Sensor Circuit
DTC C1224
- Right Rear Wheel Speed Sensor Circuit
DTC C1225
- Left Front Wheel Speed Sensor Circuit Range/Performance
DTC C1226
- Right Front Wheel Speed Sensor Circuit Range/Performance
DTC C1227
- Left Rear Wheel Speed Sensor Circuit Range/Performance
DTC C1228
- Right Rear Wheel Speed Sensor Circuit Range/Performance
Diagnostic Fault Information
Circuit/System Description
The wheel speed sensor receives ignition supply voltage from the electronic brake control module (EBCM) and provides a DC square wave signal back to the module. As the wheel spins, the EBCM uses the frequency of the square wave signal to calculate the wheel speed. The ECM may set a related chassis DTC as a result of OBD 2 emission requirements.
Conditions for Running the DTC
C0035-C0050 18
* Ignition ON.
* Ignition voltage is greater than 8 volts.
* 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.
C0035-C0050 0F or C1225-C1228
* Ignition ON.
* Ignition voltage is greater than 8 volts.
* The brake pedal is not pressed.
* A DTC is not set for the other wheel speed circuit on the same axle.
C0035-C0050 00 or C1221-C1224
* Ignition ON.
* Ignition voltage is greater than 8 volts.
Conditions for Setting the DTC
C0035-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 other.
C0035-C0050 0F or C1225-C1228
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-C0050 00 or C1221-C1224
* A short to ground or an open/high resistance is detected on the wheel speed sensor ignition voltage circuit.
* A short to voltage, a short to ground or an open/high resistance is detected on the wheel speed sensor signal circuit.
Action Taken When the DTC Sets
If equipped, the following actions occur:
* The EBCM disables the antilock brake system (ABS)/traction control system (TCS)/electronic stability control (ESC) and the hill start assist for the duration of the ignition cycle.
* A driver information center 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
* A damaged rear wheel speed sensor ring can cause failure type byte 0F (Erratic Signal) to set.
* 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 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. If the DTC returns, replace the suspected wheel speed sensor or repair the wheel speed sensor wiring.
4. 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 End Views By Name)
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
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 V between the ignition voltage circuit terminal of the appropriate sensor listed below and ground.
* Left front sensor circuit terminal 15
* Right front sensor circuit terminal 6
* Left rear sensor circuit terminal 27
* Right rear sensor circuit terminal 3
• 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 sensor circuit terminal 14
* Right front sensor circuit terminal 18
* Left rear sensor circuit terminal 28
* Right rear sensor circuit terminal 2
• 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 circuit terminal of the appropriate sensor listed below and ground.
* Left front sensor circuit terminal 15
* Right front sensor circuit terminal 6
* Left rear sensor circuit terminal 27
* Right rear sensor circuit terminal 3
• If less than the specified value, test the ignition voltage circuit for a short to ground.
5. Test for infinite resistance between the following signal circuit terminal of the appropriate sensor listed below and ground.
* Left front sensor circuit terminal 14
* Right front sensor circuit terminal 18
* Left rear sensor circuit terminal 28
* Right rear sensor circuit terminal 2
• 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 wheel speed sensor.
7. Ignition OFF, test for less than 2 ohm between the appropriate ignition voltage circuit terminals listed below.
* Left front sensor circuit terminal 15 at the EBCM harness connector and terminal A at the wheel speed sensor harness connector.
* Right front sensor circuit terminal 6 at the EBCM harness connector and terminal A at the wheel speed sensor harness connector.
* Left rear sensor circuit terminal 27 at the EBCM harness connector and terminal A at the wheel speed sensor harness connector.
* Right rear sensor circuit terminal 3 at the EBCM harness connector and terminal A 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 sensor circuit terminal 14 at the EBCM harness connector and terminal B at the wheel speed sensor harness connector.
* Right front sensor circuit terminal 18 at the EBCM harness connector and terminal B at the wheel speed sensor harness connector.
* Left rear sensor circuit terminal 28 at the EBCM harness connector and terminal B at the wheel speed sensor harness connector.
* Right rear sensor circuit terminal 2 at the EBCM harness connector and terminal B 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 wheel speed sensor. If the DTC resets, replace the EBCM.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Front Wheel Bearing and Hub Replacement (Front Suspension)
* Rear Wheel Bearing and Hub Replacement (Rear Suspension)
* Control Module References (Programming and Relearning) for EBCM replacement, programming and setup