INSPECTION PROCEDURE 3: The Front 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 blower motor
  • Malfunction of the power transistor
  • Malfunction of the A/C-ECU
  • Damaged the wiring harness or connectors

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 ).

STEP 2. M.U.T.-III diagnosis code.
Recheck if the diagnosis code is set.
(1)Erase the diagnosis code.
(2)Ignition switch: LOCK (OFF) to ON
(3)Check if the diagnosis code is set.

Q. Is the diagnosis code set?
Carry out the diagnosis code procedures. Refer to .
Go to Step 3.

STEP 3. Connector check: C-303 blower motor connector

Q. Is the check result normal?
Go to Step 4.
Repair the connector.

STEP 4. Check the blower relay.
Refer to .

Q. Is the blower relay in good condition?
Go to Step 5.
Replace the blower relay.

STEP 5. Connector check: C-115 blower motor connector

Q. Is the check result normal?
Go to Step 6.
Repair the connector.

STEP 6. Check the blower motor.
Refer to .

Q. Is the check result normal?
Go to Step 7.
Replace the blower motor.

STEP 7. Voltage measurement at C-115 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 2 and body earth. <LHD>
OK: System voltage
(4)Voltage between terminal 1 and body earth. <RHD>
OK: System voltage

Q. Is the check result normal?
Go to Step 8.
INSPECTION PROCEDURE 13: Refer to "Blower motor power supply system" .

STEP 8. Connector check: C-121 power transistor controller connector

Q. Is the check result normal?
Go to Step 9.
Repair the connector.

STEP 9. Resistance measurement at the C-121 power transistor connector.
(1)Disconnect the connector, and measure at the wiring harness side.
(2)Continuity between terminal 1 and body earth
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?
Go to Step 10.
Repair the wiring harness wires between power transistor connector terminal No. 1 and body earth.

STEP 10. Check the wiring harness between C-115 blower motor connector terminal No.2 <LHD> or 1 <RHD> and C-121 power transistor connector terminal No.2.

  • Check the power transistor power supply line for open circuit.

Q. Is the check result normal?
Go to Step 11.
Repair the wiring harness.

STEP 11. Connector check: C-111 A/C-ECU connector

Q. Is the check result normal?
Go to Step 12.
Repair the connector.

STEP 12. Check the wiring harness between C-115 blower motor connector terminal No.2 <LHD> or 1 <RHD> and C-111 A/C-ECU connector.

  • Check the blower motor power supply line for open circuit.

Q. Is the check result normal?
Go to Step 13.
Repair the wiring harness.

STEP 13. Check the wiring harness between C-121 power transistor connector terminal No.4 and C-111 A/C-ECU connector terminal No.2.

  • Check the power transistor power supply line for open circuit.

Q. Is the check result normal?
Go to Step 14.
Repair the wiring harness.

STEP 14. Replace the power transistor and recheck the trouble symptom
Check that the blower motor operates normally.

Q. Is the check result normal?
This diagnosis is complete.
Replace the A/C-ECU.