Code No. U1191 IGCT fault detection control signal not permissible



caution If diagnosis code No. U1191 is stored in the A/C control unit, be sure to carry out the CAN bus line diagnosis.
caution Before replacing ECU, ensure that the communication circuit is normal.

TROUBLE JUDGEMENT


RANGE OF CHECK
JUDGEMENT CRITERIA

FAIL SAFE, BACK UP FUNCTION




PROBABLE CAUSES




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 .) After repairing the CAN bus lines, go to Step 6.

STEP 2. M.U.T.-III diagnosis code for other systems


Check if a diagnosis code is stored in the PHEV-ECU.

Q. Is the diagnosis code stored?

Carry out the troubleshooting of the PHEV-ECU. Refer to .
Go to Step 3.

STEP 3. M.U.T.-III diagnosis code for other systems


Check whether the other ECUs, which communicate with the PHEV-ECU via CAN, have stored diagnosis code No. U1191 (Refer to ).

Q. Is the diagnosis code stored?

Go to Step 4.
Go to Step 5.

STEP 4. Check whether the diagnosis code is stored again.


Recheck if the diagnosis code is stored.

  1. Erase the stored diagnosis code.
  2. Power supply mode of the electric motor switch: OFF → ON
  3. Check the diagnosis code.

Q. Is the diagnosis code stored?

After replacing the PHEV-ECU, go to step 6.
A poor connection, open circuit or other intermittent malfunction is present in the CAN bus line between the PHEV-ECU and A/C compressor. (Refer to GROUP 00 - How to Cope with Intermittent Malfunction .)

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


Recheck if the diagnosis code is stored.

  1. Erase the stored diagnosis code.
  2. Power supply mode of the electric motor switch: OFF → ON
  3. Check the diagnosis code.

Q. Is the diagnosis code stored?

After replacing the A/C compressor, go to step 6.
A poor connection, open circuit or other intermittent malfunction is present in the CAN bus line between the PHEV-ECU and A/C compressor. (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 stored diagnosis code.
  2. Power supply mode of the electric motor switch: OFF → ON
  3. Check the diagnosis code.

Q. Is the diagnosis code stored?

Return to Step 1.
The procedure is complete.