Code No.P1034: Electrical parking lock backup power supply voltage low



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 this diagnosis code when the backup power supply fails.

PROBABLE CAUSES



  • Malfunction of CAN bus
  • Damaged harness or connector
  • Malfunction of electrical parking driver unit
  • 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 data list (Electrical parking driver unit)


Check that the following data list display contents are normal (Refer to GROUP 22D - Data List Reference Table ).
Data list
  • Item 16: Back up power supply fail flag
Check condition
Normal condition
The parking lock status
Normal
OFF
Abnormal
ON

Q. Is the check result normal?

Go to Step 6.
Go to Step 3.

STEP 3. Voltage measurement at the electrical parking driver unit connector.


(1)Disconnect the electric parking driver unit connector and measure at the wiring harness side.
(2)Voltage between BATT terminal and body earth
OK: System voltage

Q. Is the check result normal?

Go to Step 5.
Go to Step 4.

STEP 4. Check of short to earth and open circuit in the power supply line. (ETACS-ECU and electrical parking driver unit).


Q. Is the check result normal?

Go to Step 5.
Repair the connector or wiring harness.

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 electrical parking driver unit (Refer to GROUP 22D - Electrical Parking Drive Unit ).
The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).

STEP 6. 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 ).