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

The ABS-ECU is energized by the valve power supply circuit (terminal No.26). 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.26) energizes the ABS-ECU.

DIAGNOSIS CODE SET CONDITIONS

This diagnosis code is set when the ABS-ECU power supply voltage is more than 18.0 ± 1.0 V.

PROBABLE CAUSES

Battery failure
ABS-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 - CAN Bus Diagnosis table ). 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. 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.

STEP 4. Battery check

Refer to GROUP 54A - Battery Test

Q. Is the battery in good condition?

	Go to Step 5.

	Replace the battery.

STEP 5. Charging system check

Refer to GROUP 16 - Charging System

Q. Is the charging system in good condition?

	Go to Step 6.

	Repair or replace the charging system component(s).

STEP 6. Voltage measurement at the A-04 ABS-ECU connector

(1)Disconnect the ABS-ECU connector, connect special tool ABS check harness (MB991974) to the harness-side connector, and then measure the voltage at the special tool connector side.

note

Do not connect the special tool ABS check harness (MB991974) to ABS-ECU.

(2)Turn the ignition switch to the ON position.
(3)Measure the voltage between terminal No.26 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-04 ABS-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-04 ABS-ECU connector terminal No.26 and the fusible link No.27.

	NO : Repair the defective connector.

STEP 8. Resistance measurement at the A-04 ABS-ECU connector

(1)Disconnect the ABS-ECU connector, connect special tool ABS check harness (MB991974) to the harness-side connector, and then measure the resistance at the special tool connector side.

note

Do not connect the special tool ABS check harness (MB991974) to ABS-ECU.

(2)Resistance between terminal No.1 and body earth, and between terminal No.14 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-04 ABS-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-04 ABS-ECU connector terminal No.1 and body earth, and between the A-04 ABS-ECU connector terminal No.14 and body earth.

	NO : Repair the defective connector.

STEP 10. Check whether the diagnosis code is reset.

Q. Is the diagnosis code No. C2101 set?

	Replace the ABS-ECU (Refer to ).

	Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).