Code No. C2100 Abnormality in battery voltage (low 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 ).
  • 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 (Refer to , and ).

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.32) energizes the ASC-ECU.

DIAGNOSIS CODE SET CONDITIONS


This diagnosis code is set when the ASC-ECU power supply voltage drops below 9.7 ± 0.3 V during driving

PROBABLE CAUSES



  • Battery failure
  • Battery terminal looseness
  • Fusible link malfunction
  • Charging system failed
  • Damaged wiring harness and connectors
  • ASC-ECU malfunction

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 - CAN Bus Diagnosis table ). On completion, go to Step 2.

STEP 2. Diagnosis code recheck after resetting CAN bus lines


Q. Is diagnosis code No.C2100 set?

Go to Step 3.
This diagnosis is complete.

STEP 3. Fusible link check: Check fusible link No.27.


Visually check for open circuit in fusible link No.27.

Q. Is the check result normal?

Go to Step 4.
Replace fusible link No.27. Then go to Step 11.

STEP 4. Battery check


Refer to GROUP 54A - Battery Test .

Q. Is the battery in good condition?

Go to Step 5.
Charge or replace the battery. Then go to Step 11.

STEP 5. Charging system check


Refer to GROUP 16 - Charging System (2000), (2200), (2400) or (3000).

Q. Is the charging system in good condition?

Go to Step 6.
Repair or replace the charging system component(s). Then go to Step 11.

STEP 6. 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.32 and body earth.
OK: Approximately battery voltage

Q. Is the check result normal?

Go to Step 8.

Go to Step 7.

STEP 7. 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.32 and the fusible link No.27.
NO : Repair the defective connector.

STEP 8. Resistance measurement at 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 resistance at the special tool connector side.
note Do not connect the special tool ASC check harness (MB991997) to ASC-ECU.
(2)Resistance between terminal No.16 and body earth, and between terminal No.47 and body earth.
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?

Go to Step 10.

Go to Step 9.

STEP 9. Connector check: A-03 ASC-ECU connector


Q. Is the check result normal?

An open circuit may be present in the earth circuit. Repair the wiring harness between the A-03 ASC-ECU terminal No.16 and body earth, and between the A-03 ASC-ECU terminal No.47 and body earth.
NO : Repair the defective connector.

STEP 10. Check whether the diagnosis code is reset.


Q. Is the diagnosis code No. C2100 set?

Replace the ASC-ECU (Refer to ). Then go to Step 11.
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).

STEP 11. Check whether the diagnosis code is reset.


Q. Is the diagnosis code No. C2100 set?

Return to Step 1.
This diagnosis is complete.