INSPECTION PROCEDURE 5: Blower Air Amount cannot be Changed: Diagnosis

WARNING: This page is about a different car, the 2008 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.

Required Special Tools:

MB991223: Harness Set
MB992006: Extra Fine Probe

STEP 1. Check power transistor connector C-119 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is power transistor connector C-119 in good condition?

YES : Go to Step 2.

NO : Repair or replace the connector. Refer to HARNESS CONNECTOR INSPECTION . The blower motor should operate normally.
STEP 2. Measure the resistance at power transistor connector C-119.
1. Disconnect power transistor connector C-119, and measure the resistance at the wiring harness side.
2. Measure the resistance value between terminal 1 and ground.
  OK: The measured value should be 2 ohms or less
Q: Does the measured resistance value correspond with this range?

YES : Go to Step 4.

NO : Go to Step 3.

Fig 1: Measuring Resistance Value Between Terminal 1 And Ground
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 3. Check the wiring harness between power transistor connector C-119 (terminal 1) and ground.
Q: Is the wiring harness between power transistor connector C-119 (terminal 1) and ground in good condition?

YES : It can be assumed that this malfunction is intermittent. Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS .

NO : Repair the wiring harness. The blower motor should operate normally.
STEP 4. Check A/C-ECU connector C-22 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is A/C-ECU connector C-22 in good condition?

YES : Go to Step 5.

NO : Repair or replace the connector. Refer to HARNESS CONNECTOR INSPECTION . The blower motor should operate normally.
STEP 5. Check the wiring harness between A/C-ECU connector C-22 (terminals 1 and 2) and power transistor connector C-119 (terminals 2 and 4).
Q: Is the wiring harness between A/C-ECU connector C-22 (terminals 1 and 2) and power transistor connector C-119 (terminals 2 and 4) in good condition?

YES : Go to Step 6.

NO : Repair the wiring harness. The blower motor should operate normally.
STEP 6. Replace the power transistor and check the trouble symptom again
Check the trouble symptom again.

Q: Is the check result satisfactory?

YES : The procedure is complete.

NO : Replace the A/C-ECU.