Code No. P0A09: DC-DC converter (1)



caution
  • If there is any problem in the CAN bus lines, an incorrect diagnosis code may be stored. Prior to this diagnosis, diagnose the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ).
  • Whenever ECU is replaced, ensure that the CAN bus lines are normal.

TROUBLE JUDGEMENT



  • The PHEV-ECU stores diagnosis code No. P0A09 when the DC-DC converter remains deactivated because of a defective shutdown signal or its own internal error although the PHEV-ECU attempted to activate the DC-DC converter.

PROBABLE CAUSES



  • Malfunction of CAN bus line
  • Malfunction of the on board charger/DC-DC converter
  • Damaged harness or connector
  • Malfunction of PHEV-ECU

DIAGNOSIS PROCEDURE


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


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

Q. Is the check result normal?

Go to Step 2.
Repair the CAN bus lines (Refer to GROUP 54C - Troubleshooting ). On completion, go to Step 2.

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


Check whether the on board charger/DC-DC converter related diagnosis code is stored.

Q. Is the diagnosis code stored?

Diagnose the on board charger/DC-DC converter (Refer to ).
Go to Step 3.

STEP 3. Check the signal line for open and short circuit (on board charger/DC-DC converter connector and the PHEV-ECU connector).



  • Check the wiring harness between on board charger/DC-DC converter connector and the PHEV-ECU connector (DCSW terminal).

Q. Is the check result normal?

Go to Step 4.
Repair the connector or wiring harness.

STEP 4. M.U.T.-III data list


Check that the following data list display contents are normal (Refer to ).

  • Item No.44: DC-DC converter drive permission flag

Q. Is the check result normal?

Go to Step 5.
Replace the on board charger/DC-DC converter (Refer to ).

STEP 5. Check whether the diagnosis code is stored again.


Recheck if the diagnosis code is stored.
(1)Erase the diagnosis code.
(2)Turn on the power supply mode of the electric motor switch.
(3)Check if the diagnosis code is stored.

Q. Is the diagnosis code stored?

Replace the PHEV-ECU (Refer to ).
The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).