Inspection Procedure 3

INSPECTION PROCEDURE 3: Outside/Inside Air Changeover is not possible.


















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 A/C-ECU
- Damaged harness wires or connectors

DIAGNOSIS

Required Special Tools:

- MB991223: Harness Set
- MB992006: Extra Fine Probe

STEP 1. Check the defogger and A/C operations.

Q. Do the defogger and A/C work normally?

YES Go to Step 2.
NO Refer to Inspection procedure 10 "Malfunction of the A/C-ECU power supply system Inspection Procedure 2."
STEP 2. Check outside/inside air selection damper control motor connector C-106 for loose, corroded or damaged terminals, or terminals pushed back in the connector.





Q. Is outside/inside air selection damper control motor connector C-106 in good condition?

YES Go to Step 3.

NO Repair or replace the connector. Harness Connector Inspection.
Check that the outside/inside air selection damper control motor works normally.

STEP 3. Measure the voltage at outside/inside air selection damper control motor connector C-106.





(1)Disconnect outside/inside air selection damper control motor connector C-106, and measure the voltage at the harness side.
(2)Turn the ignition switch to the "ON" position.





(3)Measure the voltage between terminal 1 and ground.

- The measured value should be approximately 12 volts (battery positive voltage).

Q. Does the measured voltage correspond with this range?

YES Go to Step 5.

NO Go to Step 4.

STEP 4. Check the wiring harness between outside/inside air selection damper control motor connector C-106 (terminal 1) and the ignition switch (IG2).













NOTE:
Also check joint connector C-03, junction block connectors C-211 and C-215 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-03, junction block connector C-211 or C-215 is damaged, repair or replace the connector as described in Harness Connector Inspection Harness Connector Inspection.

- Check the motor power supply line for open circuit.

Q. Is the wiring harness between outside/inside air selection damper control motor connector C-106 (terminal 1) and the ignition switch (IG2) in good condition?

YES It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions.

NO Repair the wiring harness. Check that the outside/inside air selection damper control motor works normally.

STEP 5. Check the outside/inside air selection damper control motor.





CAUTION:
Cut off the battery voltage when the damper is in the inside/outside air position.

Check the outside/inside air selection damper control motor by the following procedures.





Q. Does outside/inside air selection damper control motor work normally?

YES Go to Step 6.

NO Replace the outside/inside air selection damper control motor. Check that the outside/inside air selection damper control motor works normally.

STEP 6. Check A/C-ECU connector C-15 for loose, corroded or damaged terminals, or terminals pushed back in the connector.





Q. Is A/C-ECU connector C-15 in good condition?

YES Go to Step 7.

NO Repair or replace the connector. Harness Connector Inspection.
Check that the outside/inside air selection damper control motor works normally.

STEP 7. Check the wiring harness between outside/inside air selection damper control motor connector C-106 (terminals 4 and 5) and A/C-ECU C-15
(terminals 5 and 6).





- Check the motor power supply line for open circuit.

Q. Are the wiring harness between outside/inside air selection damper control motor connector C-106 (terminals 4 and 5) and A/C-ECU C-15 (terminals 5 and 6) in good condition?

YES Go to Step 8.

NO Repair the wiring harness. Check that the outside/inside air selection damper control motor works normally.

STEP 8. Retest the system.

Q. Does a malfunction take place again?

YES Replace the A/C-ECU, and check that the outside/inside air selection damper control motor works normally.
NO It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions.