Anti-Lock Braking System (ABS)

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 CAN Bus Diagnostics Chart ).
- Whenever ECU is replaced, ensure that the CAN bus lines are normal.

CIRCUIT 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.

DTC SET CONDITIONS

This DTC is set when the ABS-ECU power supply voltage is more than 18.0 ± 1.0 volts.

PROBABLE CAUSES

- Battery failure
- ABS-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
- MB991974: ABS check harness

STEP 1. Using scan tool MB991958, diagnose the CAN bus line.

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 CAN Bus Diagnostics Chart).
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

Battery Test.

Q. Is the battery in good condition?

YES Go to Step 5.
NO Replace the battery. Then go to Step 4.
STEP 4. Charging system check

Generator Output Line Voltage Drop Test.

Q. Is the charging system in good condition?

YES Go to Step 5.
NO Repair or replace the charging system component(s).
STEP 5. Check whether the DTC is reset.

Erase the DTC.

Q. Is DTC C2101 set?

YES Replace the hydraulic unit (integrated with ABS-ECU) (Refer to Anti-Lock Braking System (ABS)).
Then go to Step 6.
NO Intermittent malfunction How to Cope With Intermittent Malfunctions).
STEP 6. Check whether the DTC is reset.

Erase the DTC.

Q. Is DTC C2101 set?

YES Return to Step 1.
NO The procedure is complete.