C2101

DTC C2101 Abnormality in battery voltage (high voltage)

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 (Refer to Diagnostic trouble code diagnosis Diagnostic Trouble Code Descriptions).
^ Whenever ECU is replaced, ensure that the CAN bus lines are normal.
^ When the hydraulic unit (integrated with ASC-ECU) is replaced, always carry out the calibration of the steering wheel sensor, the G and yaw rate sensor and brake fluid pressure sensor.

OPERATION
The ASC-ECU is energized by the valve power supply circuit (terminal No.32). When the power is supplied from the ignition switch (IG1) to the IG1 relay in ETACS-ECU, IG1 relay is turned on. At this time, the valve power supply circuit (terminal No.4) energizes the ASC-ECU.

DTC SET CONDITIONS
This DTC is set when the ASC-ECU power supply voltage is more than 18.0 ± 1.0 V.

PROBABLE CAUSES
^ Battery failure
^ ASC-ECU malfunction
^ Charging system failed
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.
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 (Refer to Diagnosis - CAN Bus Diagnostic Table CAN Bus Diagnostics Table). On completion, go to Step 2.

STEP 2. DTC recheck after resetting CAN bus lines
Q: Is DTC C2101 set?
YES: Go to Step 3.
NO: The procedure is complete.

STEP 3. Battery check
Refer to Battery Test Battery Test.
Q: Is the battery in good condition?
YES: Go to Step 5.
NO: Charge or replace the battery. Then go to Step 4.

STEP 4. Charging system check
Refer to Charging System Charging System.
Q: Is the check result normal?
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 C2101 set?
YES: Replace the hydraulic unit (ASC-ECU). Then go to Step 6.
NO: The trouble can be an intermittent malfunction.

STEP 6. Check whether the DTC is reset.
Q: Is DTC C2101 set?
YES: Return to Step 1.
NO: The procedure is complete.