Circuit Description
The wheel speed sensor produces an alternating current signal whose amplitude and frequency vary, depending on the velocity of the wheel. The electronic brake control module (EBCM) uses the frequency of the AC signal to calculate the wheel speed.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC C0035 Left Front Wheel Speed Sensor Circuit Malfunction |
| • | DTC C0036 Left Front Wheel Speed Sensor Circuit Range/Performance |
| • | DTC C0040 Right Front Wheel Speed Sensor Circuit Malfunction |
| • | DTC C0041 Right Front Wheel Speed Sensor Circuit Range/Performance |
| • | DTC C0045 Left Rear Wheel Speed Sensor Circuit Malfunction |
| • | DTC C0046 Left Rear Wheel Speed Sensor Circuit Range/Performance |
| • | DTC C0050 Right Rear Wheel Speed Sensor Circuit Malfunction |
| • | DTC C0051 Right Rear Wheel Speed Sensor Circuit Range/Performance |
Conditions for Running the DTC
C0035, C0040, C0045, C0050
The ignition is ON.
C0036, C0041, C0046, C0051
| • | Vehicle speed is over 40 km/h (25 mph). |
| • | The brake pedal is not pressed. |
| • | The antilock brake system (ABS) is not active. |
Conditions for Setting the DTC
C0035, C0040, C0045, C0050
One of the following conditions exists for 0.02 seconds:
| • | The DTC will set if one wheel equals 0 while the other wheel speeds are greater than 40 km/h (25 mph). |
| • | A short to voltage exists in the wheel speed sensor (WSS) in one of the WSS circuits. |
| • | An open exists in the wheel speed sensor signal circuit. |
| • | A short to ground--The wheel speed sensor signal circuit is shorted to ground. |
C0036, C0041, C0046, C0051
All of the following conditions exists for 0.02 seconds:
| • | The DTC will set if one wheel speed is less than 2.75 km/h (1.7 mph), and the other WSS are greater than 40 km/h (25 mph). |
| • | The brake pedal is not pressed. |
| • | DTC C0035, C0040, C0045, and C0050 is not set. |
| • | The DTC will set if there is interference on the wheel speed circuits for 20 seconds with the brake pedal applied or 5 seconds when the brake pedal is not applied. |
Action Taken When the DTC Sets
If equipped, the following actions occur:
| • | The EBCM disables the ABS and traction control system (TCS) for the duration of the ignition cycle. |
| • | A DTC malfunction will set. |
| • | The ABS telltale turns ON. |
| • | The traction control switch light emitting diode (LED) will turn OFF. |
Conditions for Clearing the DTC
| • | The condition for the DTC is no longer present. |
| • | Using a scan tool, clear the DTC function. |
| • | The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles. |
Diagnostic Aids
C0035, C0040, C0045, C0050
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 354 ml (12 oz) 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.
C0036, C0041, C0046, C0051
A possible cause of this DTC is electrical noise on the wheel speed sensor harness wiring. Electrical noise could result from the wheel speed sensor wires being routed to close to high energy ignition system components, such as spark plug wires.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests the wheel speed sensor for the proper resistance value.
-
This step ensures that the wheel speed sensor generates the proper voltage.
Step
| Action | Value(s) | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics Connector End View Reference: Antilock Brake System Connector End Views | ||||||||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |||||||||
2 |
Does the scan tool indicate that this wheel speed DTC set? | 64 km/h (40 mph) | Go to Step 3 | Go to Diagnostic Aids | ||||||||
Does the resistance measure within the specified range? | 800-1700 ohms | Go to Step 4 | Go to Step 8 | |||||||||
Does the AC voltage measure greater than the specified value? | 100 mV | Go to Step 5 | Go to Step 8 | |||||||||
5 | Inspect for poor connections at the harness connector of the wheel speed sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 6 | ||||||||
6 |
Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 7 | ||||||||
7 | Inspect for poor connections at the harness connector for the EBCM. Refer Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 9 | ||||||||
8 | Replace the wheel speed sensor. Refer to Front Wheel Bearing and Hub Replacement and Rear Wheel Bearing and Hub Replacement . Did you complete the replacement? | -- | Go to Step 10 | -- | ||||||||
9 | Replace the EBCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the repair? | -- | Go to Step 10 | -- | ||||||||
10 |
Does the DTC reset? | -- | Go to Step 2 | System OK | ||||||||
