The driving approval and driving state control of the DC-DC converter are performed by
the EV-ECU.
DIAGNOSIS CODE SET CONDITIONS
When the DC-DC converter drive stop state continues for
4 seconds or longer while the DC-DC converter driving approval is underway, the diagnosis code
No. P0A09 will be set.
COMMENT ON PAST TROUBLE
When the malfunction of the system cooling system or control voltage trouble is recorded
as a past trouble, the diagnosis code may be set. Check the code.
Conduct the actuator test (item 03: Water pump drive,
item 04: Radiator fan 1 drive, item 05: Radiator fan 2 drive) to check the cooling system.
Visually check the radiator core.
Check the EMCU diagnosis code.
When the total battery voltage is around the low voltage limit, MCU may determine
that a malfunction has occurred (not a malfunction).
PROBABLE CAUSES
Damaged wiring harness or connector(s)
Malfunction of system cooling
Malfunction of the DC-DC converter
Malfunction of the EV-ECU
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-III data list
Check the BMU service data. (Refer to .)
Data list
Item No. 7 : Battery total voltage
OK: 210 V or more
Q.
Is the check result normal?
Go to Step 2.
Charge the main battery. Then go to Step 10.
STEP 2. Measure the voltage at E-03 on board charger/DC-DC
converter connector.
(1)Disconnect the E-03 on board charger/DC-DC converter connector, and measure
the voltage at the wiring harness side.
(2)Turn the electric motor switch to the "ON" position.
(3)Measure the voltage between the E-03 on board charger/DC-DC converter
connector terminal No. 8 and the body earth. OK: Battery voltage
Q.
Is the check result normal?
Go to Step 5.
Go to Step 3.
STEP 3. Connector check: A-08X EV control relay (relay box) connecter,
B-27 intermediate connector, E-03 on board charger/DC-DC converter connector
Q.
Is the check result normal?
Go to Step 4.
Repair the damaged connector. Or, correct or replace the relay box.
STEP 4. Check the wiring harness between A-08X EV control relay (relay
box) connector terminal No. 1 and E-03 on board charger/DC-DC converter connector terminal
No. 8.