Inspection Procedure 9

INSPECTION PROCEDURE 9: Blower Motor power supply system.














TECHNICAL DESCRIPTION (COMMENT)

If the voltage is not supplied to the blower motor, the blower relay system may be failed.

TROUBLESHOOTING HINTS

- Malfunction of the ETACS-ECU
- Malfunction of the blower relay
- Damaged harness wires or connectors

DIAGNOSIS

Required Special Tools:

- MB991223: Harness Set
- MB992006: Extra Fine Probe

STEP 1. Check blower relay connector C-303 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Is blower relay connector C-303 in good condition?

YES Go to Step 2.
NO Repair or replace the connector. Harness Connector Inspection.
STEP 2. Check the blower relay continuity.

Follow the table below to check the blower relay for continuity.









Q. Is the blower relay in good condition?

YES Go to Step 3.

NO Replace the rear window defogger relay.

STEP 3. Measure the voltage at blower relay connector C-303.

(1)Disconnect blower relay connector C-303, and measure the voltage at the junction block side.





(2)Measure the voltage between terminals 1 and ground.

- The measured value should be approximately 12 volts (battery positive voltage).





(3)Measure the voltage between terminals 4 and ground.

- The measured value should be approximately 12 volts (battery positive voltage).

Q. Is the measured voltage approximately 12 volts?

YES Go to Step 5.

NO Go to Step 4.

STEP 4. Check the wiring harness between blower relay connector C-303
(terminals 1 and 4) and the fusible link (37).

NOTE:
Also check ETACS-ECU connector C-309 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If ETACS-ECU connector C-309 is damaged, repair or replace the connector as described in Harness Connector Inspection Harness Connector Inspection.

- Check the blower relay power supply line for open circuit.

Q. Is the wiring harness between blower relay connector C-303 (terminals 1 and 4) and the fusible link (37) in good condition?

YES It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions.
NO Repair or replace the wiring harness. Harness Connector Inspection.
STEP 5. Check blower relay connector C-115 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Is blower relay connector C-115 in good condition?

YES Go to Step 6.
NO Repair or replace the connector. Harness Connector Inspection.
STEP 6. Check the wiring harness between blower relay connector C-303
(terminal 3) and blower motor connector C-115 (terminal 1).

NOTE:
Also check ETACS-ECU connector C-315 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If ETACS-ECU connector C-315 is damaged, repair or replace the connector as described in Harness Connector Inspection Harness Connector Inspection.

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

Q. Is the wiring harness between blower relay connector C-303 (terminal 3) and blower motor connector C-115 (terminal 1) in good condition?

YES It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions.
NO Repair or replace the wiring harness. Harness Connector Inspection.