[Previous][Next]
INSPECTION PROCEDURE 3: The blower does not work
 
 
 
 
TECHNICAL DESCRIPTION (COMMENT)
If the blower motor does not operate, the blower motor circuit system may be defective.
 
 
 
TROUBLESHOOTING HINT
  • Malfunction of the blower motor
  • Malfunction of the power transistor
  • Malfunction of the A/C controller assembly (A/C-ECU)
  • The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
 
 
 
DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Using scan tool (M.U.T.-IIISE), DTC check.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Ignition switch: "LOCK" (OFF) to "ON"
(3) Check if the DTC is set.
Is the DTC set?
Carry out the diagnostic trouble code procedures (Refer to ).
Go to Step 2.
 
STEP 2. Check the blower relay.
Refer to .
Is the blower relay in good condition?
Go to Step 3.
Replace the blower relay.
 
STEP 3. Check the blower motor.
Refer to .
Is the check result normal?
Go to Step 4.
Replace the blower motor.
 
STEP 4. 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 power supply terminal and body ground.
OK: System voltage
Is the check result normal?
Go to Step 5.
Refer to inspection procedure 7 "Blower motor power supply system" .
 
STEP 5. Resistance measurement at the power transistor connector.
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Continuity between ground terminal and body ground.
OK: Continuity exists (2 Ω or less)
Is the check result normal?
Go to Step 6.
Repair the wiring harness wires between power transistor connector ground terminal and body ground.
 
STEP 6. Check of open circuit in power transistor line between blower motor connector and power transistor connector.
Is the check result normal?
Go to Step 7.
Repair the connector(s) or wiring harness.
 
STEP 7. Check of open circuit in P/TB and P/TC line between blower motor connector, power transistor connector and A/C controller assembly (A/C-ECU) connector.
Is the check result normal?
Go to Step 8.
Repair the connector(s) or wiring harness.
 
STEP 8. Recheck the trouble symptom.
Is the check result normal?
This diagnosis is complete.
Replace the A/C controller assembly (A/C-ECU).