Code No. C2101 Abnormality in battery voltage (high voltage)









caution If there is any problem in the CAN bus lines, an incorrect diagnosis code may be set. Prior to this diagnosis, diagnose the CAN bus lines (Refer to GROUP 54C, Trouble code diagnosis ).

OPERATION


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 ASC-ECU power supply signal is sent to ASC-ECU (terminal No. 4) from the fusible link No. 33 through the multi-purpose fuse No. 12.

DIAGNOSIS CODE SET CONDITIONS


This diagnosis code 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 PROCEDURE


STEP 1. M.U.T.-III CAN bus diagnosis


Use M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?

Go to Step 3.
Repair the CAN bus lines (Refer to GROUP 54C - Troubleshooting ). On completion, go to Step 2.

STEP 2. Diagnosis code recheck after resetting CAN bus lines


Q. Is the diagnosis code No. C2101 set?

Go to Step 3.
This diagnosis is complete.

STEP 3. Battery check


Refer to GROUP 54A - Battery Test .

Q. Is the battery in good condition?

Go to Step 4.
Charge or replace the battery.

STEP 4. Charging system check


Refer to GROUP 16 - Charging System .

Q. Is the charging system in good condition?

Go to Step 5.
Repair or replace the charging system component(s).

STEP 5. Voltage measurement at the A-03 ASC-ECU connector



(1)Disconnect the ASC-ECU connector, connect special tool ASC check harness (MB991997) to the harness-side connector, and then measure the voltage at the special tool connector side.
note Do not connect the special tool ASC check harness (MB991997) to ASC-ECU.
(2)Turn the ignition switch to the ON position.
(3)Measure the voltage between terminal No. 4 and body earth.
OK: Approximately battery voltage

Q. Is the check result normal?

Go to Step 7.

Go to Step 6.

STEP 6. Connector check: A-03 ASC-ECU connector


Q. Is the check result normal?

The open or short circuit may be present in the power supply circuit. Repair the wiring harness between the A-03 ASC-ECU connector terminal No. 4 and the fusible link No. 33.
NO : Repair the defective connector.

STEP 7. Check whether the diagnosis code is reset.


Q. Is the diagnosis code No. C2101 set?

Replace the ASC-ECU.
This diagnosis is complete.