INSPECTION PROCEDURE 2: The blower does not work




COMMENTS ON TROUBLE SYMPTOM


If the blower motor does not operate, the blower motor circuit system may be defective.

PROBABLE CAUSES



  • Malfunction of the fuse
  • Malfunction of the fusible link
  • Malfunction of the blower relay
  • Malfunction of the blower motor
  • Malfunction of the blower switch
  • Malfunction of the heater controller assembly
  • Damaged wiring harness or connector

DIAGNOSIS PROCEDURE


STEP 1. M.U.T.-III diagnosis code for other systems.


Use M.U.T.-III to check that the diagnosis code is set in the engine-ECU.

Q. Is the diagnosis code set?

Carry out the diagnosis for the diagnosis code.
Go to Step 2.

STEP 2. Check the fuse (23).


Q. Is the fuse (23) in good condition?

Go to Step 4.
Go to Step 3.

STEP 3. Check short circuit in blower motor line between blower relay and blower motor connector.


note Before the wiring harness check, check the junction block connector.

Q. Is the check result normal?

Replace the fuse (23).
Repair or replace the connector(s) or wiring harness.

STEP 4. Check the fusible link (2).


Q. Is the fusible link (2) in good condition?

Go to Step 6.
Go to Step 5.

STEP 5. Check short circuit in fusible link line between fuse (23) and fusible link (2).


note Before the wiring harness check, check the junction block connector.

Q. Is the check result normal?

Replace the fusible link (2).
Repair or replace the connector(s) or wiring harness.

STEP 6. Check the blower relay.


Refer to .

Q. Is the blower relay in good condition?

Go to Step 7.
Replace the blower relay.

STEP 7. Check the blower motor.


Refer to .

Q. Is the blower motor in good condition?

Go to Step 8.
Replace the blower motor (Refer to ).

STEP 8. Check the blower switch.


Refer to .

Q. Is the blower switch in good condition?

Go to Step 9.
Replace the heater controller assembly (Refer to ).

STEP 9. Voltage measurement at blower motor connector.


(1)Disconnect the connector, and measure at the wiring harness side.
(2)Turn the ignition switch to the "ON" position.
(3)Voltage between terminal 1 and body earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 11.
Go to Step 10.

STEP 10. Check open circuit in blower motor line between blower relay and blower motor connector.


note Before the wiring harness check, check the junction block connector.

Q. Is the check result normal?

Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Repair or replace the connector(s) or wiring harness.

STEP 11. Resistance measurement at the blower relay connector.


(1)Disconnect the connector, and measure at the wiring harness side.
(2)Continuity between terminal 2 and body earth
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?

Go to Step 13.
Go to Step 12.

STEP 12. Check open circuit in blower relay earth line between blower relay connector and body earth.


note Before the wiring harness check, check the junction block connector and joint connector.

Q. Is the check result normal?

Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Repair or replace the connector(s) or wiring harness.

STEP 13. Resistance measurement at the blower switch connector.


(1)Disconnect the connector, and measure at the wiring harness side.
(2)Continuity between terminal 3 and body earth
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?

Go to Step 15.
Go to Step 14.

STEP 14. Check open circuit in blower switch earth line between blower switch connector and body earth.


Q. Is the check result normal?

Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Repair or replace the connector(s) or wiring harness.

STEP 15. Retest the system


Q. Is the check result normal?

Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Return to Step 1.