STEP 1. Using scan tool MB991958, diagnose the CAN bus lines.
STEP 2. DTC recheck after resetting CAN bus lines
(1) Drive the vehicle at 12 mph (20 km/h) or higher.note | The ABS warning light does not turn OFF in some cases unless the vehicle runs at 12 mph (20 km/h) or higher. |
(2) Turn the ignition switch from the ON position to the LOCK (OFF) position.
Is DTC C100A set?
Go to Step 3. The procedure is complete.
STEP 3. Using scan tool MB991958, check the data list
STEP 4. Voltage measurement at the A-03 ASC-ECU connector (Short circuit to power supply)
(1) Disconnect the ASC-ECU connector, connect special tool test harness (MB991709) to the harness-side connector, and then measure the voltage at the special tool connector side.note | Do not connect the special tool to ASC-ECU. |
(2) Turn the ignition switch to the ON position.
(3) Measure the voltage between the wheel speed sensor power supply terminal (signal terminal) No.36 and the body ground and between the wheel speed sensor ground terminal No.37 and the body ground.OK: 1 Volt or less
Is the check result normal?
Go to Step 5. (Not normal at the terminal No.45 or 46) :
Go to Step 6.
STEP 5. Resistance measurement at A-03 ASC-ECU connector (Short circuit to ground)
(1) Disconnect the ASC-ECU connector, connect special tool test harness (MB991709) to the harness-side connector, and then measure the resistance at the special tool connector side.note | Do not connect the special tool to ASC-ECU. |
(2) Measure the resistance between the wheel speed sensor power supply terminal (signal terminal) No.36 and the body ground and between the wheel speed sensor ground terminal No.37 and the body ground.OK: No continuity
Is the check result normal?
Go to Step 8. (Not normal at the terminal No.36 or 37) :
Go to Step 6.
STEP 6. Connector check: A-03 ASC-ECU connector, A-15 front wheel speed sensor <LH> connector
STEP 7. Wiring harness check between A-03 ASC-ECU connector terminal No.36 and A-15 front wheel speed sensor <LH> connector terminal No.1 and between A-03 ASC-ECU connector terminal No.37 and A-15 front wheel speed sensor <LH> connector terminal No.2.
STEP 8. Voltage and current measurement at A-15 front wheel speed sensor <LH> connector (Open circuit)
(1) Disconnect the A-15 front wheel speed sensor <LH> connector, and measure at the wiring harness side.
(2) Turn the ignition switch to the ON position.
(3) Measure the voltage between the power supply terminal of A-15 front wheel speed sensor <LH> connector terminal No. 1 and the body ground.
(4) Measure the output current at the special tool test harness (MB991709) to connect between the A-15 front wheel speed sensor <LH> connector and the wiring harness connector (Refer to ).OK:
- <Voltage> System voltage
- <Current> 5 - 9 mA or 11 - 17 mA
Is the check result normal?
Go to Step 10. Go to Step 9.
STEP 9. Wiring harness check between A-03 ASC-ECU connector terminal No.36 and A-15 front wheel speed sensor <LH> connector terminal No.1 and between A-03 ASC-ECU connector terminal No.37 and A-15 front wheel speed sensor <LH> connector terminal No.2.
STEP 10. Check for wheel speed sensor <FL> as a single unit
STEP 11. Connector check: A-03 ASC-ECU connector, A-15 front wheel speed sensor <LH> connector
STEP 12. Check whether the diagnostic trouble code is set again.