C2111

DTC C2111: Brake fluid pressure sensor power supply circuit (low input)
DTC C2112: Brake fluid pressure sensor power supply circuit (high input)

CAUTION:
^ If there is any problem in the CAN bus lines, an incorrect diagnostic trouble code may be set. Prior to this diagnosis, diagnose the CAN bus lines.
^ Whenever the ECU is replaced, ensure that the CAN bus lines are normal.
^ When the hydraulic unit (integrated with ASC-ECU) is replaced, always perform the calibration of steering wheel sensor, G and yaw rate sensor, brake fluid pressure sensor, cut valve, and inlet valve.

CIRCUIT OPERATION
When the brake pedal is depressed, the master cylinder pressure sensor integrated in the hydraulic unit detects the brake fluid pressure applied from the master cylinder. At the same time, it converts the pressure value into voltage signal, and outputs the signal.

DTC SET CONDITIONS
If the voltage supplied to the master cylinder pressure sensor is outside the standard value range, these diagnostic trouble codes are set.

PROBABLE CAUSES
ASC-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. Using scan tool MB991958, diagnose the CAN bus lines.
Using scan tool MB991958, diagnose the CAN bus lines.
Q: Is the check result normal?
YES: Go to Step 3.
NO: Repair the CAN bus lines. (Refer to Troubleshooting Can Bus Diagnostics Table.) After repairing the CAN bus line, go to Step 2.

STEP 2. DTC recheck after repairing the CAN bus line
Q: Is DTC C2111 or C2112 set?
YES: Go to Step 3.
NO: This diagnosis is complete.

STEP 3. Battery check
Refer to Battery Test Battery Test.
Q: Is the battery in good condition?
YES: Go to Step 4.
NO: Charge or replace the battery.

STEP 4. Charging system check
Refer to Charging System Charging System Diagnosis.
Q: Is the charging system in good condition?
YES: Go to Step 5.
NO: Repair or replace the charging system component(s).

STEP 5. Check whether the DTC is reset.
Q: Is DTC C2111 or C2112 set?
YES: Replace the hydraulic unit (incorporates in ASC-ECU). Then go to Step 6.
NO: Intermittent malfunction.

STEP 6. Check whether the DTC is reset.
Q: Is DTC C2111 or C2112 set?
YES: Return to Step 1.
NO: The procedure is complete.