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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 wiring harness or connectors
 
 
 
DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Check blower relay connector C-402 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Is blower relay connector C-402 in good condition?
Go to Step 2.
Repair or replace the connector. Refer to GROUP 00E, Harness Connector Inspection .
 
STEP 2. Check the blower relay continuity.
Follow the table below to check the blower relay for continuity.
 
Battery voltageTester connectionSpecified condition
Not applied3 - 4Open circuit
  • Connect terminal 1 to the positive battery terminal
  • Connect terminal 2 to the negative battery terminal
3 - 4Less than 2 ohms
Is the blower relay in good condition?
Go to Step 3.
Replace the rear window defogger relay.
 
STEP 3. Measure the voltage at blower relay connector C-402.
(1) Disconnect blower relay connector C-402, 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).
Is the measured voltage approximately 12 volts?
Go to Step 5.
Go to Step 4.
 
STEP 4. Check the wiring harness between blower relay connector C-402 (terminals 1 and 4) and the fusible link (37).
noteAlso check ETACS-ECU connector C-408 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If ETACS-ECU connector C-408 is damaged, repair or replace the connector as described in GROUP 00E, Harness Connector Inspection .
  • Check the blower relay power supply line for open circuit.
Is the wiring harness between blower relay connector C-402 (terminals 1 and 4) and the fusible link (37) in good condition?
It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions .
Repair or replace the wiring harness. Refer to GROUP 00E, Harness Connector Inspection .
 
STEP 5. Check blower relay connector C-402 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Is blower relay connector C-402 in good condition?
Go to Step 6.
Repair or replace the connector. Refer to GROUP 00E, Harness Connector Inspection .
 
STEP 6. Check the wiring harness between blower relay connector C-402 (terminal 3) and blower motor connector C-213 (terminal 1).
noteAlso check ETACS-ECU connector C-415 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If ETACS-ECU connector C-415 is damaged, repair or replace the connector as described in GROUP 00E, Harness Connector Inspection .
  • Check the blower motor power supply line for open circuit.
Is the wiring harness between blower relay connector C-402 (terminal 3) and blower motor connector C-213 (terminal 1) in good condition?
It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions .
Repair or replace the wiring harness. Refer to GROUP 00E, Harness Connector Inspection .