ABS

DTC C104B: Abnormality in FL wheel inlet valve system

DTC C104F: Abnormality in FR wheel inlet valve system

DTC C1053: Abnormality in RL wheel inlet valve system

DTC C1057: Abnormality in RR wheel inlet valve system

DTC C105F: Abnormality in FL wheel outlet valve system

DTC C1063: Abnormality in FR wheel outlet valve system

DTC C1067: Abnormality in RL wheel outlet valve system

DTC C105B: Abnormality in RR wheel outlet valve system

CAUTION
^ If there is any problem in the CAN bus lines, an incorrect DTC may be set. Prior to this diagnosis, diagnose the CAN bus lines.
^ Whenever ECU is replaced, ensure that the CAN bus lines are normal.

CIRCUIT OPERATION
^ ABS-ECU contains the power supply circuit (terminal No.26) for the solenoid valve. The solenoid valve is energized by the valve relay, which is incorporated in ABS-ECU.
^ The valve relay, which is incorporated in ABS-ECU, is always energizing the solenoid valve unless the initial check is in progress when the ignition switch is turned on, or the recurrent system check is in progress.
^ ABS-ECU activates the solenoid valve by turning on its driving transistor.

DTC SET CONDITIONS
These DTCs will be set under the conditions below:
^ The solenoid valve is not energized even after ABS-ECU has turned on the driving transistor (Open circuit is present in the power supply circuit to the ABS-ECU solenoid valve, or the valve relay has failed).
^ After ABS-ECU has turned off the driving transistor, the solenoid valve still remains energized (short in the solenoid valve circuit).
^ When a solenoid valve failure is detected

PROBABLE CAUSES
^ ABS-ECU malfunction

DIAGNOSIS

Required Special Tools:
^ MB991958: Scan Tool (M.U.T.-III Sub Assembly)
^ MB991824: Vehicle Communication Interface (V.C.I.)
^ MB991827: M.U.T.-III USB Cable
^ MB991910: M.U.T.-III Main Harness A

STEP 1. M.U.T.-III CAN bus diagnostics
Use scan tool to diagnose the CAN bus lines.

Q: Is the check result normal?
YES: Go to Step 3.
NO: Repair the CAN bus lines. On completion, go to Step 2.

STEP 2. DTC recheck after resetting CAN bus lines

Q: Is the relevant DTC set?
YES: Go to Step 3.
NO: The procedure is complete.

STEP 3. Check whether the DTC is reset.

Q: Is the relevant DTC set?
YES: Replace the hydraulic unit (ABS-ECU). Then go to Step 4.
NO: Intermittent malfunction.

STEP 4. Check whether the DTC is reset.

Q: Is the relevant DTC set?
YES: Return to Step 1.
NO: The procedure is complete.