Diagnostic Routine AJ
Diagnostic Routine AJ
Diagnostic Overview
Wheel Speed Sensor Electrical Fault DTCs - Front
Refer to Wiring Diagram Set 42 for schematic and connector information Electrical Diagrams.
Normal Operation and Fault Conditions
Active wheel speed sensors generate a square wave signal proportional to wheel speed which is sent to the ABS (Anti-Lock Brake System) module. Each wheel speed sensor is connected to the ABS (Anti-Lock Brake System) module through 2 wires and a connector at each wheel speed sensor. One wire is for sensor voltage supply from the ABS (Anti-Lock Brake System) and the other wire is for the signal return to the ABS (Anti-Lock Brake System). With the ignition ON, the ABS (Anti-Lock Brake System) module carries out a self-test by sending a reference voltage through the wheel speed sensors and their circuitry.
DTC (Diagnostic Trouble Code) Fault Trigger Conditions
Visual Inspection and Diagnostic Pre-checks
- Make sure the wheel speed sensor harness is routed correctly and is undamaged.
- Make sure the wheel speed sensor electrical connector is free from any corrosion or other contaminates.
Special Tool(s)
Pinpoint Test
1. CHECK FOR FAULT REPEATABILITY
1. Ignition ON.
2. Using a scan tool, clear all ABS (Anti-Lock Brake System) module DTCs (Diagnostic Trouble Codes).
3. Ignition OFF.
4. Ignition ON.
5. Test drive the vehicle above 20 km/h (12.4 mph) for at least 5 minutes. This will allow the ABS (Anti-Lock Brake System) module to carry out a system check.
6. Bring the vehicle to a safe stop.
7. Using a scan tool, carry out the ABS (Anti-Lock Brake System) module self-test.
Is DTC (Diagnostic Trouble Code) C0031:11, C0031:15, C0034:11 and/or C0034:15 present?
2. CHECK THE ABS (Anti-Lock Brake System) MODULE OUTPUT USING THE ROTUNDA ACTIVE WHEEL SPEED SENSOR TESTER
1. Ignition OFF.
2. Disconnect the suspect Wheel Speed Sensor electrical connector.
3. Connect the Rotunda Active Wheel Speed Sensor Tester to the wheel speed sensor connectors.
4. Ignition ON.
5. Select the correct system polarity on the Rotunda Active Wheel Speed Sensor Tester and turn the power switch to the ON position.
Is the tester output LED (Light-emitting Diode) illuminated?
3. CHECK THE WHEEL SPEED SENSOR FOR A SHORT TO VOLTAGE WITH THE ROTUNDA ACTIVE WHEEL SPEED SENSOR TESTER
1. Observe the current overload LED (Light-emitting Diode) on the Rotunda Active Wheel Speed Sensor Tester.
Is the current overload LED (Light-emitting Diode) illuminated?
4. CHECK THE WHEEL SPEED SENSOR OUTPUT WITH THE ROTUNDA ACTIVE WHEEL SPEED SENSOR TESTER
1. Raise the suspect wheel until it can spin freely. REFER to Lifting Points .
2. While monitoring the Rotunda Active Wheel Speed Sensor Tester, slowly spin the suspect wheel.
Do the sensor output LEDs (Light-emitting Diodes) illuminate and flash?
5. CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR A SHORT TO BATTERY VOLTAGE
1. Ignition OFF.
2. Disconnect ABS (Anti-Lock Brake System) Module electrical connector.
3. Disconnect the suspect Wheel Speed Sensor.
4. Ignition ON.
5. For the LF (Left Front) wheel speed sensor, measure:
6. For the RF (Right Front) wheel speed sensor, measure:
Is any voltage present?
6. CHECK THE WHEEL SPEED CIRCUITS FOR AN OPEN
1. Ignition OFF.
2. For the LF (Left Front) wheel speed sensor, measure:
3. For the RF (Right Front) wheel speed sensor, measure:
Are the resistances less than 3 ohms?
7. CHECK FOR SHORTED WHEEL SPEED SENSOR CIRCUITS
1. Ignition OFF.
2. Disconnect ABS (Anti-Lock Brake System) Module electrical connector (if not previously disconnected).
3. Disconnect the suspect Wheel Speed Sensor (if not previously disconnected).
4. For the LF (Left Front) wheel speed sensor, measure:
5. For the RF (Right Front) wheel speed sensor, measure:
Is the resistance greater 10,000 ohms?
8. CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR A SHORT TO GROUND
1. For the LF (Left Front) wheel speed sensor, measure:
2. For the RF (Right Front) wheel speed sensor, measure:
Are the resistances greater than 10,000 ohms?
9. CHECK THE ABS (Anti-Lock Brake System) MODULE OUTPUT
1. Ignition OFF.
2. Connect ABS (Anti-Lock Brake System) Module electrical connector.
3. Ignition ON.
4. For the LF (Left Front) wheel speed sensor, measure:
5. For the RF (Right Front) wheel speed sensor, measure:
Is the voltage greater 10 volts?
10. CHECK FOR CORRECT ABS (Anti-Lock Brake System) MODULE OPERATION
1. Ignition OFF.
2. Disconnect and inspect the ABS (Anti-Lock Brake System) module electrical connector (if not previously disconnected).
3. Repair:
- corrosion (install new connector or terminal - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary
4. Connect the ABS (Anti-Lock Brake System) module electrical connector. Make sure it seats and latches correctly.
5. Operate the system and determine if the concern is still present.
Is the concern still present?
