TCS or ACS

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.
^ 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 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 C21 01 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.