• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Left Front Sensor 12 Volt Reference | C0035 00 | C0035 08 | C0035 00 | C0035 0A, 0F, 08 |
Left Front Sensor Signal | C0035 00 | C0035 08 | C0035 00 | C0035 0A, 0F, 08 |
Right Front Sensor 12 Volt Reference | C0040 00 | C0040 00 | C0040 00 | C0040 0A 0F, 08 |
Right Front Sensor Signal | C0040 00 | C0040 00 | C0040 00 | C0040 0A 0F, 08 |
Left Rear Sensor 12 Volt Reference | C0045 00 | C0045 00 | C0045 00 | C0045 0A 0F, 08 |
Left Rear Sensor Signal | C0045 00 | C0045 00 | C0045 00 | C0045 0A 0F, 08 |
Right Rear Sensor 12 Volt Reference | C0050 00 | C0050 00 | C0050 00 | C0050 0A 0F, 08 |
Right Rear Sensor Signal | C0050 00 | C0050 00 | C0050 00 | C0050 0A 0F, 08 |
The wheel speed sensor receives ignition 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.
Ignition ON.
• | Engine Running. |
• | A DTC is not set for the other wheel speed sensor on the same axle. |
• | A short to ground, or an open/high resistance is detected on the wheel speed sensor voltage circuit. |
• | A short to voltage, short to ground or an open/high resistance is detected on the signal circuit. |
• | An erratic signal output of the wheel speed sensor is detected. |
• | Wheel speed too high |
• | An erratic signal output of the wheel speed sensor is detected. |
• | Wheel speed too low |
• | If equipped the EBCM disables the antilock brake system (ABS) / traction control system (TCS) / vehicle stability enhancement system (VSES) for the duration of the ignition cycle. |
• | The EBCM sends a serial data message to illuminate the warning indicator/message. |
• | The condition for setting the DTC is no longer present and the vehicle is driven at a speed over 13 km/h (8 mph). |
• | The EBCM clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles. |
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:
Antilock Brake System Schematics
Control Module References for scan tool information
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).
• | LF Sensor circuit terminal 9 |
• | RF Sensor circuit terminal 5 |
• | LR Sensor circuit terminal 3 |
• | RR Sensor circuit terminal 11 |
⇒ | If greater than the specified value, test the 12 volt reference circuit for a short to voltage. |
• | LF Sensor circuit terminal 8 |
• | RF Sensor circuit terminal 6 |
• | LR Sensor circuit terminal 2 |
• | RR Sensor circuit terminal 12 |
⇒ | If greater than the specified value, test the signal circuit for a short to voltage. |
• | LF Sensor circuit terminal 9 |
• | RF Sensor circuit terminal 5 |
• | LR Sensor circuit terminal 3 |
• | RR Sensor circuit terminal 11 |
⇒ | If less than the specified value, test the 12 volt reference circuit for a short to ground. |
• | LF Sensor circuit terminal 8 |
• | RF Sensor circuit terminal 6 |
• | LR Sensor circuit terminal 2 |
• | RR Sensor circuit terminal 12 |
⇒ | If less than the specified value, test the signal circuit for a short to ground. |
• | LF sensor circuit terminal 9 at the EBCM harness connector and terminal 1 at the WSS harness connector |
• | RF sensor circuit terminal 5 at the EBCM harness connector and terminal 1 at the WSS harness connector |
• | LR sensor circuit terminal 3 at the EBCM harness connector and terminal 1 at the WSS harness connector |
• | RR sensor circuit terminal 11 at the EBCM harness connector and terminal 1 at the WSS harness connector |
⇒ | If greater than the specified value, test the 12 volt reference circuit for an open or high resistance. |
• | LF sensor circuit terminal 8 at the EBCM harness connector and terminal 2 at the WSS harness connector |
• | RF sensor circuit terminal 6 at the EBCM harness connector and terminal 2 at the WSS harness connector |
• | LR sensor circuit terminal 2 at the EBCM harness connector and terminal 2 at the WSS harness connector |
• | RR sensor circuit terminal 12 at the EBCM harness connector and terminal 2 at the WSS harness connector |
⇒ | If greater than the specified value, test the signal circuit for an open or high resistance. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for EBCM replacement, setup, and programming |