INSPECTION PROCEDURE 4: The blower air volume cannot be changed: Diagnosis

WARNING: This page is about a different car, the 2014 Mitsubishi Outlander. However, it is still accessible from the selected car via links, so may be relevant.

STEP 1. Using scan tool (M.U.T.-III), diagnose the CAN bus line
CAUTION: To prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
1. Connect scan tool (M.U.T.-III). Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-III)
2. Turn the ignition switch to the "ON" position.
3. Diagnose the CAN bus line.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the CAN bus line found to be normal?
1. YES: Go to Step 2.
2. NO: Repair the CAN bus line (Refer to DIAGNOSIS ).
STEP 2. Using scan tool (M.U.T.-III), DTC check.
Check that the diagnostic trouble code related to the air conditioning is not stored.

Q: Is the diagnostic trouble code stored?
1. YES: Carry out the diagnostic trouble code procedures. Refer to DIAGNOSTIC TROUBLE CODE CHART .
2. NO: Go to Step 3.
STEP 3. Resistance measurement at the power transistor connector.
1. Disconnect the connector, and measure at the wiring harness side.
2. Continuity between terminal 1 and body ground
  OK: Continuity exists (2 Ω or less)
Q: Is the check result normal?
1. YES: Go to Step 4.
2. NO: Repair the wiring harness wires between power transistor connector terminal and body ground.
STEP 4. Check of open circuit in P/TB, P/TC and E line between blower motor, power transistor, ground J/C (DASH) and heater controller assembly (A/C-ECU) connector.
Q: Is the check result normal?
1. YES: Go to Step 5.
2. NO: Repair the connector(s) or wiring harness.
STEP 5. Replace the power transistor and recheck the trouble symptom
Check that the blower motor operates normally.

Q: Is the check result normal?
1. YES: This diagnosis is complete.
2. NO: Replace the heater controller assembly (A/C-ECU).