Without Scan Tool
- Turn ignition off. Using a fused jumper wire or Service Connector (SST 09843-18020), connect Data Link Connector No. 1 (DLC1) terminals Ts and E1. See Figure. DLC1 is located on left side of engine compartment, behind ECM box. Start engine. ABS warning light should blink once every .13 second. If ABS warning light does not blink, check ABS warning light circuit. See ABS WARNING LIGHT CIRCUIT under SYSTEM TESTS.
- Lightly depress brake pedal for more than one second. Quickly and firmly depress brake pedal. ABS warning light should come on for 3 seconds. Drive vehicle at 28 MPH or more for several seconds in a straight line. ABS warning light should go off. Stop vehicle. Using another fused jumper wire or Service Connector (SST 09843-18020), connect DLC1 terminals Tc and E1. See Figure. There should now be 2 jumper wires.
- Observe ABS warning light. If system is normal, ABS warning light will blink every .25 second. If system is malfunctioning, ABS warning light will begin to flash a 2-digit Diagnostic Trouble Code (DTC). ABS warning light will blink every .5 second with a .5 second pause between blinks. ABS warning light will flash first digit, followed by a 1.5 second pause and then light will flash second digit.
- Count number of flashes to obtain digits of 2-digit code. If 2 or more codes are stored, a 2.5 second pause will separate codes. If 2 or more malfunctions are indicated at the same time, lowest numbered DTC will be displayed first.
- Identify DTC and probable cause. See SPEED SENSOR DIAGNOSTIC TROUBLE CODE IDENTIFICATION table. Repair as necessary. Turn ignition off. Remove fused jumper wires or Service Connectors (SST 09843-18020) from DLC1.
SPEED SENSOR DIAGNOSTIC TROUBLE CODE IDENTIFICATION
| Scan Tool DTC/ABS Warning Light DTC | Description | Probable Cause |
|---|---|---|
| C1271/71 | Right Front Speed Sensor Signal Voltage Low | Defective Right Front Speed Sensor, Incorrect Sensor Installation Or Defective Sensor Rotor |
| C1272/72 | Left Front Speed Sensor Signal Voltage Low | Defective Left Front Speed Sensor, Incorrect Sensor Installation Or Defective Sensor Rotor |
| C1273/73 | Right Rear Speed Sensor Signal Voltage Low | Defective Right Rear Speed Sensor, Incorrect Sensor Installation Or Defective Sensor Rotor |
| C1274/74 | Left Rear Speed Sensor Signal Voltage Low | Defective Left Rear Speed Sensor, Incorrect Sensor Installation Or Defective Sensor Rotor |
| C1275/75 | Abnormal Change In Output Signal Voltage From Right Front Speed Sensor | Defective Right Front Sensor Rotor |
| C1276/76 | Abnormal Change In Output Signal Voltage From Left Front Speed Sensor | Defective Left Front Sensor Rotor |
| C1277/77 | Abnormal Change In Output Signal Voltage From Right Rear Speed Sensor | Defective Right Rear Sensor Rotor |
| C1278/78 | Abnormal Change In Output Signal Voltage From Left Rear Speed Sensor | Defective Left Rear Sensor Rotor |