Code No. P1B2B: Electric water pump power supply relay open/short



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. P1B2B when the power relay (water/oil pump relay) circuit for the electric water pump fails (open circuit or short to earth).

PROBABLE CAUSES



  • Malfunction of the water/oil pump relay (noise interference)
  • 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 3.
Repair the CAN bus lines (Refer to GROUP 54C - Troubleshooting ). On completion, go to Step 2.

STEP 2. 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?

Go to Step 3.
The procedure is complete.

STEP 3. M.U.T.-III actuator test


Conduct the actuator test, and check the electric water/oil pump relay. (Refer to .)

  1. Erase the stored diagnosis code.
  2. Turn on the power supply mode of the electric motor switch.
    note The READY (ready to drive) indicator should not illuminate at a vehicle speed of 0 km/h (vehicle stationary).
Actuator test
  • Item No. 9: Water/oil pump power supply relay
OK: The electric water pump/oil relay works normally.

Q. Is the check result normal?

Go to Step 8.
Go to Step 4.

STEP 4. Water/oil pump relay check


Refer to-GROUP 14B - On vehicle service, Water/oil pump relay check .

Q. Is the check result normal?

Go to Step 5.
Replace the damaged water/oil pump relay.

STEP 5. Voltage measurement at PHEV-ECU connector (WPR- terminal).


(1)Disconnect the connector, and measure at the wiring harness side.
(2)Measure the voltage between the PHEV-ECU connector (WPR- terminal) and body earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 6.
Go to Step 7.

STEP 6. Check the power supply line for open circuit. (IGCT relay and the water/oil pump relay).



  • Check the wiring harness between IGCT relay and the water/oil pump relay terminal No 2 connector.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
Repair the connector or wiring harness.

STEP 7. Check the signal line for short circuit (water/oil pump relay connector and PHEV-ECU connector).



  • Check the wiring harness between water/oil pump relay connector (No.1 terminal) and the PHEV-ECU (WPR- terminal) connector.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
Repair the connector or wiring harness.

STEP 8. 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 procedure is complete.