Circuit Description
As the wheel spins, the wheel speed sensor produces an AC signal. 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 |
| • | DTC C0036 Left Front Wheel Speed Sensor Circuit Range/Performance |
| • | DTC C0037 Left Front Wheel Speed Sensor Circuit Low |
| • | DTC C0040 Right Front Wheel Speed Sensor Circuit |
| • | DTC C0041 Right Front Wheel Speed Sensor Circuit Range/Performance |
| • | DTC C0042 Right Front Wheel Speed Sensor Circuit Low |
| • | DTC C0045 Left Rear Wheel Speed Sensor Circuit |
| • | DTC C0046 Left Rear Wheel Speed Sensor Circuit Range/Performance |
| • | DTC C0047 Left Rear Wheel Speed Sensor Circuit Low |
| • | DTC C0050 Right Rear Wheel Speed Sensor Circuit |
| • | DTC C0051 Right Rear Wheel Speed Sensor Circuit Range/Performance |
| • | DTC C0052 Right Rear Wheel Speed Sensor Circuit Low |
Conditions for Running the DTC
C0035, C0040, C0045, or C0050
The ignition is ON.
C0036, C0037, C0041, C0042, C0046, C0047, C0051, or C0052
| • | DTCs C0035, C0040, C0045, or C0050 are not set. |
| • | The brake pedal is not pressed. |
| • | The ABS is not active. |
| • | At least two wheel speeds are not 0 km/h. |
Conditions for Setting the DTC
C0035, C0040, C0045, or C0050
The EBCM detects an open, short to ground or a short to power on the wheel speed sensor signal circuit or the low reference circuit.
C0036, C0041, C0046, or C0051
The EBCM detects a rapid variation in the wheel speed. The wheel speed changes by 16 km/h (10 mph) or more in 0.01 second. The change must occur 3 times with no more than 0.2 seconds between occurrences.
C0037, C0042, C0047, or C0052
| • | The suspect wheel speed equals zero. |
| • | The other wheel speeds are greater than 8 km/h (5 mph). |
| • | The other wheel speeds are within 11 km/h (7 mph) of each other. |
Action Taken When the DTC Sets
If equipped, the following actions occur:
| • | The EBCM disables the ABS/traction control system (TCS)/vehicle stability enhancement system (VSES) for the duration of the ignition cycle. |
| • | The dynamic rear proportion (DRP) does not function optimally. |
| • | The ABS indicator turns ON. |
| • | The Traction Control indicator turns ON. |
| • | The driver information center (DIC) displays the Service Stability System message. |
Conditions for Clearing the DTC
| • | The condition for the DTC is no longer present and the DTC is cleared with a scan tool. |
| • | The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles. |
Diagnostic Aids
C0035, C0037, C0040, C0042, C0045, C0047, C0050 or C0052
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 (9.9 ml) 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, or 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.
-
Measure the resistance of the wheel speed sensor in order to determine if the sensor has a valid resistance value.
-
Ensures that the wheel speed sensor is generating a valid AC voltage output.
Step | Action | Values | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics | ||||||||||||
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? | 8 km/h (5 mph) | Go to Step 3 | Go to Diagnostic Aids | ||||||||
Does the resistance measure within the specified range? | 850-1350 ohms | Go to Step 4 | Go to Step 8 | |||||||||
Does the A/C 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 Circuit Testing 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 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 9 | ||||||||
8 | Replace the wheel speed sensor. Refer to the appropriate procedure: 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 replacement? | -- | Go to Step 10 | -- | ||||||||
10 |
Does the DTC reset? | -- | Go to Step 2 | System OK | ||||||||
