Inspection Procedure 4

INSPECTION PROCEDURE 4: Outside/Inside Air Changeover Is Not Possible [Vehicles Without A/C]

Outside/Inside Damper Control Motor Circuit:

CIRCUIT OPERATION
If the outside/inside air selection damper control motor does not operate normally, the outside/inside air selection damper control motor system may be defective.

TROUBLESHOOTING HINTS
- Malfunction of the outside/inside air selection damper control motor
- Malfunction of the heater control module
- Damaged harness wires or connectors

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A

STEP 1. Using scan tool MB991958, check for diagnostic trouble code.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

Check if an heater control module DTC is set.







1. Connect scan tool MB991958. Refer to "How to connect the Scan Tool (M.U.T.-III)." How to Connect the Scan Tool (M.U.T.-III)
2. Turn the ignition switch to the "ON" position.
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC set?

YES : Refer to DIAGNOSTIC TROUBLE CODE CHART. Diagnostic Trouble Code Descriptions

NO : Go to Step 2.

STEP 2. Check outside/inside air selection damper control motor connector C-111 and heater control module connector C-52 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are outside/inside air selection damper control motor connector C-111 and heater control module connector C-52 in good condition?

YES : Go to Step 3.

NO : Repair or replace the connector. Check that the A/C works normally.

STEP 3. Check the wiring harness between heater control module connector C-52 (terminal 26, 25, 27, 24 and 29) and outside/inside air selection damper control motor connector C-111 (terminals 2, 5, 4. 1 and 3).

- Check the heater control module signal line for open and short circuit.

Q: Are the wiring harness between heater control module connector C-52 (terminal 26, 25, 27, 24 and 29) and outside/inside air selection damper control motor connector C-111 (terminals 2, 5, 4. 1 and 3) in good condition?

YES : Go to Step 4.

NO : Repair the wiring harness. Check that the A/C works normally.

STEP 4. Replace the outside/inside air selection damper control motor 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 heater control module.