Speed Sensor Diagnostics
NOTE:
While diagnosing speed sensors, system functions as a standard brake system.
NOTE:
If speed sensor diagnostics cannot be entered, check Tc terminal circuit. See Tc TERMINAL CIRCUIT under CIRCUIT TESTS .
- Ensure battery voltage is about 12 volts. Turn ignition on. ABS light should come on, then go out after about 3 seconds. If ABS light does not come on, check fuse, bulb, and wiring harness.
- Turn ignition off. DO NOT remove short pin from Data Link Connector (DLC). Connect DLC terminals Ts and E1. See Figure. Engage parking brake. Start engine. Verify ABS light flashes 4 times per second.
- Drive vehicle straight ahead at speed greater than 28 MPH. Stop vehicle. Connect jumper between DLC terminals Tc and E1. See Figure. If no malfunction is detected, ABS light blinks 4 times a second. If a malfunction is detected, 4 seconds will elapse, then ABS light will begin to flash a 2-digit DTC. First series of flashes indicates first digit of DTC. After a 1.5 second pause, second series of flashes indicates second digit of DTC.
- If 2 or more DTCs are stored, there will be a 2.5-second pause between each DTC. After all DTCs are flashed, there will be a 4-second pause, then all DTCs will repeat.
- Record DTCs. Turn ignition off. Check appropriate speed sensor circuit, speed sensor installation and speed sensor rotor. Repair as necessary. See SPEED SENSOR DTCS table. Remove jumper wires from DLC. Clear DTCs. See CLEARING DTCS .
SPEED SENSOR DTCS
| DTC | Malfunctioning Circuit |
|---|---|
| 71 | Low Output Voltage Of Right Front Speed Sensor Signal |
| 72 | Low Output Voltage Of Left Front Speed Sensor Signal |
| 73 | Low Output Voltage Of Right Rear Speed Sensor Signal |
| 74 | Low Output Voltage Of Left Rear Speed Sensor Signal |
| 75 | Abnormal Output Signal From Right Front Speed Sensor |
| 76 | Abnormal Output Signal From Left Front Speed Sensor |
| 77 | Abnormal Output Signal From Right Rear Speed Sensor |
| 78 | Abnormal Output Signal From Left Rear Speed Sensor |