Code No. P1AF4: Control power supply voltage abnormality (BMU)


caution If there is any problem in the CAN bus lines, an incorrect diagnosis code may be set. Prior to this diagnosis, always diagnose the CAN bus lines.

OPERATION



  • BMU communicates with EV-ECU via CAN.

DIAGNOSIS CODE SET CONDITIONS



  • When the diagnosis code No. P1A4C or No. P1A4D is set to the BMU, the diagnosis code No. P1AF4 will be set.

PROBABLE CAUSES



  • Malfunction of the BMU power supply system

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnosis
Use the M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?
Go to Step 3.
Repair the CAN bus line. (Refer to GROUP 54C - Troubleshooting .) Then go to Step 2.

STEP 2. Diagnosis code recheck after resetting CAN bus lines
Check again if the diagnosis code No. P1AF4 is set to the EV-ECU.
(1)Erase the stored diagnosis code.
(2)Set the electric motor switch from the LOCK (OFF) position to the ON position.
(3)Check if the diagnosis code is set.

Q. Is the diagnosis code set?
Go to Step 3.
This diagnosis is complete.

STEP 3. Use M.U.T.-III to confirm a diagnosis code of other systems.
Check if the diagnosis code No. P1A4C or P1A4D is set to the BMU.

Q. Is the diagnosis code set?
Carry out troubleshooting for the diagnosis code No. P1A4C (refer to ) or No. P1A4D (refer to ). Then go to Step 4.
Go to Step 4.

STEP 4. Diagnosis code recheck
Check again if the diagnosis code is set to the EV-ECU.
(1)Erase the stored diagnosis code.
(2)Set the electric motor switch from the LOCK (OFF) position to the ON position.
(3)Check if the diagnosis code is set.

Q. Is the diagnosis code set?
Return to Step 1.
The diagnosis is complete.