Code No. P1A19: MCU shutdown circuit (internal trouble)


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



  • The EV-ECU controls the IGBT gate in the MCU by outputting the gate shutdown signal to the MCU. The MCU transmits the gate status to the EV-ECU as a shutdown signal.

DIAGNOSIS CODE SET CONDITIONS



  • If the gate shutdown signal set by the EV-ECU differs from the shutdown status signal received from the MCU for 1 second or longer, the diagnosis code No. P1A19 will be set.

PROBABLE CAUSES



  • Malfunction of the MCU

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. P1A19 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. ?Check whether the diagnosis code is set.
Check if the diagnosis code No. P1A18 for other systems is set to the EV-ECU.

Q. Is the diagnosis code set?
Carry out troubleshooting for the diagnosis code P1A18. (Refer to .)
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?
Replace the MCU.(Refer to .) Then go to Step 5.
Intermittent malfunction. (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction .)

STEP 5. 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.