STEP 1. Voltage measurement at the ASC-ECU connector (FL+, FL-, FR+, FR-, RL+, RL-, RR+, RR- terminal)
(1) Disconnect the ASC-ECU connector, and measure at the wiring harness side.
(2) Turn the ignition switch to the "ON" position.DTC C100A is set
- Measure the voltage between the ASC-ECU connector (FL+ terminal) and the body ground, and between the ASC-ECU connector (FL- terminal) and the body ground.
OK: 1 volt or less
DTC C1015 is set
- Measure the voltage between the ASC-ECU connector (FR+ terminal) and the body ground, and between the ASC-ECU connector (FR- terminal) and the body ground.
OK: 1 volt or less
DTC C1020 is set
- Measure the voltage between the ASC-ECU connector (RL+ terminal) and the body ground, and between the ASC-ECU connector (RL- terminal) and the body ground.
OK: 1 volt or less
DTC C102B is set
- Measure the voltage between the ASC-ECU connector (RR+ terminal) and the body ground, and between the ASC-ECU connector (RR- terminal) and the body ground.
OK: 1 volt or less
Is the check result normal?
Go to Step 3. Go to Step 2.
STEP 2. Voltage measurement at the ASC-ECU connector.
(1) Disconnect the ASC-ECU connector and wheel speed sensor connector, and measure at the wiring harness side of the ASC-ECU connector.
(2) Turn the ignition switch to the "ON" position.DTC C100A is set
- Measure the voltage between the ASC-ECU connector (FL+ terminal) and the body ground, and between the ASC-ECU connector (FL- terminal) and the body ground.
OK: 1 volt or less
DTC C1015 is set
- Measure the voltage between the ASC-ECU connector (FR+ terminal) and the body ground, and between the ASC-ECU connector (FR- terminal) and the body ground.
OK: 1 volt or less
DTC C1020 is set
- Measure the voltage between the ASC-ECU connector (RL+ terminal) and the body ground, and between the ASC-ECU connector (RL- terminal) and the body ground.
OK: 1 volt or less
DTC C102B is set
- Measure the voltage between the ASC-ECU connector (RR+ terminal) and the body ground, and between the ASC-ECU connector (RR- terminal) and the body ground.
OK: 1 volt or less
Is the check result normal?
Replace the wheel speed sensor (Refer to <front> or <rear>). Repair the connector(s) or wiring harness.
STEP 3. Resistance measurement at ASC-ECU connector (FL+, FL-, FR+, FR-, RL+, RL-, RR+, RR- terminal)
Disconnect the ASC-ECU connector, and measure at the wiring harness side of the ASC-ECU connector.DTC C100A is set
- Measure the resistance between the ASC-ECU connector (FL+ terminal) and the body ground, and between the ASC-ECU connector (FL- terminal) and the body ground.
OK: No continuity
DTC C1015 is set
- Measure the resistance between the ASC-ECU connector (FR+ terminal) and the body ground, and between the ASC-ECU connector (FR- terminal) and the body ground.
OK: No continuity
DTC C1020 is set
- Measure the resistance between the ASC-ECU connector (RL+ terminal) and the body ground, and between the ASC-ECU connector (RL- terminal) and the body ground.
OK: No continuity
DTC C102B is set
- Measure the resistance between the ASC-ECU connector (RR+ terminal) and the body ground, and between the ASC-ECU connector (RR- terminal) and the body ground.
OK: No continuity
Is the check result normal?
Go to Step 5. Go to Step 4.
STEP 4. Resistance measurement at ASC-ECU connector.
Disconnect the ASC-ECU connector and wheel speed sensor connector, and measure at the wiring harness side of the ASC-ECU connector.DTC C100A is set
- Measure the resistance between the ASC-ECU connector (FL+ terminal) and the body ground, and between the ASC-ECU connector (FL- terminal) and the body ground.
OK: No continuity
DTC C1015 is set
- Measure the resistance between the ASC-ECU connector (FR+ terminal) and the body ground, and between the ASC-ECU connector (FR- terminal) and the body ground.
OK: No continuity
DTC C1020 is set
- Measure the resistance between the ASC-ECU connector (RL+ terminal) and the body ground, and between the ASC-ECU connector (RL- terminal) and the body ground.
OK: No continuity
DTC C102B is set
- Measure the resistance between the ASC-ECU connector (RR+ terminal) and the body ground, and between the ASC-ECU connector (RR- terminal) and the body ground.
OK: No continuity
Is the check result normal?
Replace the wheel speed sensor (Refer to <front> or <rear>). Repair the connector(s) or wiring harness.
STEP 5. Resistance measurement at ASC-ECU connector.
Disconnect the ASC-ECU connector and wheel speed sensor connector, and measure at the wiring harness side of the ASC-ECU connector.DTC C100A is set
- Measure the resistance between the ASC-ECU connector (FL+ terminal) and (FL- terminal).
OK: No continuity
DTC C1015 is set
- Measure the resistance between the ASC-ECU connector (FR+ terminal) and (FR- terminal).
OK: No continuity
DTC C1020 is set
- Measure the resistance between the ASC-ECU connector (RL+ terminal) and (RL- terminal).
OK: No continuity
DTC C102B is set
- Measure the resistance between the ASC-ECU connector (RR+ terminal) and (RR- terminal).
OK: No continuity
Is the check result normal?
Go to Step 6. Repair the connector(s) or wiring harness.
STEP 6. Voltage measurement at the wheel speed sensor connector.
(1) Disconnect the wheel speed sensor connector, and measure at the wiring harness side.
(2) Turn the ignition switch to the "ON" position.DTC C100A is set
- Measure the voltage between the wheel speed sensor connector (FL+ terminal) and the body ground.
OK: The voltage should measure approximately 12 volts (battery positive voltage).
DTC C1015 is set
- Measure the voltage between the wheel speed sensor connector (FR+ terminal) and the body ground.
OK: The voltage should measure approximately 12 volts (battery positive voltage).
DTC C1020 is set
- Measure the voltage between the wheel speed sensor connector (RL+ terminal) and the body ground.
OK: The voltage should measure approximately 12 volts (battery positive voltage)
DTC C102B is set
- Measure the voltage between the wheel speed sensor connector (RR+ terminal) and the body ground.
OK: The voltage should measure approximately 12 volts (battery positive voltage)
Is the check result normal?
Go to Step 8. Go to Step 7.
STEP 7. Resistance measurement at ASC-ECU connector and wheel speed sensor.
Disconnect the ASC-ECU connector and wheel speed sensor connector, and measure at the wiring harness side of the ASC-ECU connector and wheel speed sensor connector.DTC C100A is set
- Check of open circuit in FL+ line between ASC-ECU connector and front wheel speed sensor (LH) connector.
OK: The resistance should be 2 ohms or less
DTC C1015 is set
- Check of open circuit in FR+ line between ASC-ECU connector and front wheel speed sensor (RH) connector.
OK: The resistance should be 2 ohms or less
DTC C1020 is set
- Check of open circuit in RL+ line between ASC-ECU connector and rear wheel speed sensor (LH) connector.
OK: The resistance should be 2 ohms or less
DTC C102B is set
- Check of open circuit in RR+ line between ASC-ECU connector and rear wheel speed sensor (RH) connector.
OK: The resistance should be 2 ohms or less
Is the check result normal?
Go to Step 11. Repair the connector(s) or wiring harness.
STEP 8. Current measurement at each wheel speed sensors connector.
STEP 9. Resistance measurement at ASC-ECU connector and wheel speed sensor.
Disconnect the ASC-ECU connector and wheel speed sensor connector, and measure at the wiring harness side of the ASC-ECU connector and wheel speed sensor connector.DTC C100A is set
- Check of open circuit in FL- line between ASC-ECU connector and front wheel speed sensor (LH) connector.
OK: The resistance should be 2 ohms or less
DTC C1015 is set
- Check of open circuit in FR- line between ASC-ECU connector and front wheel speed sensor (RH) connector.
OK: The resistance should be 2 ohms or less
DTC C1020 is set
- Check of open circuit in RL- line between ASC-ECU connector and rear wheel speed sensor (LH) connector.
OK: The resistance should be 2 ohms or less
DTC C102B is set
- Check of open circuit in RR- line between ASC-ECU connector and rear wheel speed sensor (RH) connector.
OK: The resistance should be 2 ohms or less
Is the check result normal?
Go to Step 10. Repair the connector(s) or wiring harness.
STEP 10. Check for wheel speed sensor as a single unit
STEP 11. Check whether the DTC is set again.
(1) Erase the DTC.
(2) Turn the ignition switch to the "LOCK" (OFF) position.
(3) Turn the ignition switch to the "ON" position.
(4) Drive the vehicle at 20 km/h (12 mph) or higher.note | The ABS warning light does not turn OFF in some cases unless the vehicle runs at 20 km/h (12 mph) or higher. |
Is DTC C100A, C1015, C1020 or C102B set?
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ). Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/How to Cope with Intermittent Malfunctions ).