Code No.C1861: ABS-ECU Power Supply Low Voltage


caution If there is any problem in the CAN bus lines, an incorrect diagnosis code may be set. Diagnose the CAN bus lines before the diagnosis codes (Refer to GROUP 54C, CAN bus-line diagnostic flow ).

OPERATION



  • The ABS-ECU is energized by the ignition switch (IG1) through multi-purpose fuse 15 and the ABS-ECU terminal 32.
  • Power supply for ABS solenoid valve is supplied to the ABS-ECU terminal 12 via fusible link 21.
  • Power supply for ABS motor is supplied to the ABS-ECU terminal 34 via fusible link 22.

DIAGNOSIS CODE SET CONDITIONS



PROBABLE CAUSES



  • Battery abnormality
  • Charging system failed

DIAGNOSIS

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


caution Before connecting or disconnecting the M.U.T.-III, turn the ignition switch to the "LOCK" (OFF) position.
(1)Connect M.U.T.-III to the 16-pin diagnosis connector.
(2)Turn the ignition switch to the "ON" position.
(3)Diagnose the CAN bus line.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the check result normal?

Go to Step 3.

Repair the CAN bus line (Refer to GROUP 54C, CAN bus line Diagnostic flow ). Then go to Step 2.

STEP 2. M.U.T.-III diagnosis code


caution Before connecting or disconnecting the M.U.T.-III, turn the ignition switch to the "LOCK" (OFF) position.
(1)Turn the ignition switch to the "ON" position.
(2)Erase the diagnosis code.
(3)Turn the ignition switch to the "LOCK" (OFF) position.
(4)Turn the ignition switch to the "ON" position.
(5)Check if the diagnosis code is set.
(6)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is code No.C1861 set?

Go to Step 3.

The procedure is complete.

STEP 3. Check the battery.
Check the battery (Refer to GROUP 54A, Battery test ).

Q. Is the check result normal?
Go to Step 4.
Charge or replace the battery.

STEP 4. Check the charging system.
Check the charging system (Refer to GROUP 16, Charging system ).

Q. Is the check result normal?
Go to Step 5.
Repair or replace the charging system component(s). Then go to Step 6.

STEP 5. Check whether the diagnosis code is reset.


caution Before connecting or disconnecting the M.U.T.-III, turn the ignition switch to the "LOCK" (OFF) position.
Check again if the diagnosis code is set.
(1)Turn the ignition switch to the "ON" position.
(2)Erase the diagnosis code.
(3)Turn the ignition switch to the "LOCK" (OFF) position.
(4)Turn the ignition switch to the "ON" position.
(5)Check if the diagnosis code is set.
(6)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is code No.C1861 set?

Replace the hydraulic unit (integrated with ABS-ECU). Then go to Step 6.

It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction .

STEP 6. Check whether the diagnosis code is reset.


caution Before connecting or disconnecting the M.U.T.-III, turn the ignition switch to the "LOCK" (OFF) position.
Check again if the diagnosis code is set.
(1)Turn the ignition switch to the "ON" position.
(2)Erase the diagnosis code.
(3)Turn the ignition switch to the "LOCK" (OFF) position.
(4)Turn the ignition switch to the "ON" position.
(5)Check if the diagnosis code is set.
(6)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is code No.C1861 set?

Go to Step 1.

The procedure is complete.