Inspection Procedure 2: Heater does not work at all, heater does not work quickly.




PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. The heater controller assembly (A/C-ECU) M.U.T.-III service data


Check that the following service data M.U.T.-III display contents are normal. (Refer to .)

  • Item 154: Set temperature at driver’s side
  • Item 69: Blower motor (target value)

Q. Is the check result normal?

Go to Step 2.
Replace the heater controller assembly (A/C-ECU).

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


Check if diagnosis code is stored in the heater controller assembly (A/C-ECU).

  • DTC: B1115

Q. Is the diagnosis code stored?

Carry out the diagnosis code procedures. Refer to .
NO <Vehicles with electric heater> : Go to Step 3.
NO <Vehicles without electric heater> : Go to Step 6.

STEP 3. Check of open circuit in SENG, +12V, WTSI, WTSO, HTR1, HTR2, HTR3 line between electric heater connector and heater controller assembly (A/C-ECU) connector.


Q. Is the check result normal?

Go to Step 4.
Repair the connector(s) or wiring harness.

STEP 4. Check the high-voltage connector and wiring harness.


danger Carry out the check on the high-voltage circuit while reading carefully the precautions on handling a high-voltage vehicle. Refer to.
danger Wear the specified protection equipment during the check.
1.Shut down the high voltage. (Refer to GROUP 00 - Precautions before Service - Precautions on handling high-voltage vehicle .)
2.Check the following terminal (bolt).

3.Check the following wiring harnesses for short circuit.

Q. Is the check result normal?

Go to Step 5.
NO : Replace the wiring harness.

STEP 5. Check the heater water valve assembly <Vehicles with electric heater >.


Check the heater water valve assembly <Vehicles with electric heater>. Refer to .

Q. Is the check result normal?

Go to Step 6.
Replace the heater water valve assembly.

STEP 6. After replacing the electric heater, check again that the heater works normally


Q. Is the check result normal?

This diagnosis is complete.
Go to Step 7.

STEP 7. After replacing the heater controller assembly (A/C-ECU), check again that the heater works normally.


Q. Is the check result normal?

This diagnosis is complete.
Replace the heater controller assembly (A/C-ECU). Check the trouble symptom again, and if it does not work correctly, return to Step 1.