Mode Door

TROUBLE DIAGNOSIS


Mode Door Motor Circuit


SYMPTOM:
- Air outlet does not change.
- Mode door motor does not operate normally.

INSPECTION FLOW
1. CONFIRM SYMPTOM BY PERFORMING OPERATIONAL CHECK - DISCHARGE AIR
1. Turn mode dial to all five positions.
2. Confirm that discharge air comes out according to the air distribution table. Refer to Discharge Air Flow.
Can a symptom be duplicated?
YES >> GO TO 3.
NO >> GO TO 2.
2. PERFORM COMPLETE OPERATIONAL CHECK
Perform a complete operational check and check for any symptoms. Refer to Operational Check.
Can a symptom be duplicated?
YES >> Refer to Initial Inspection and Diagnostic Overview.
NO >> System OK.
3. CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 4.
4. CHECK MODE DOOR OPERATION
Check and verify mode door mechanism for smooth operation in each mode.
OK or NG
OK >> GO TO 5.
NG >> Repair as necessary.
5. CHECK LAN SYSTEM CIRCUIT
Perform diagnostic procedure for the LAN system. Refer to LAN System Circuit.
OK or NG
OK >> If the symptom still exists, perform a complete operational check. Refer to Operational Check. If no other symptom exists replace front air control. Refer to Service and Repair.
NG >> Repair as necessary.

SYSTEM DESCRIPTION

Component Parts

Mode door control system components are:
- Front air control
- Mode door motor (LCU)

System Operation
The front air control receives signals from its various dials and switches. The front air control then sends air mix door, mode door and intake door motor opening angle data to the air mix door motor LCU, mode door motor LCU and intake door motor LCU.
The mode door motor reads their respective signals according to the address signal. Opening angle indication signals received from the front air control and each of the motor position sensors are compared by the LCU's in each motor with the existing decision and opening angles. Subsequently, HOT/COLD or DEFROST/VENT or FRESH/RECIRCULATION operation is selected. The new selection data is returned to the front air control.






COMPONENT DESCRIPTION

Mode Door Motor
The mode door motor (1) is attached to the heater and cooling unit assembly. It rotates so that air is discharged from the outlet set by the front air control. Motor rotation is conveyed to a link which activates the mode door.






DIAGNOSTIC PROCEDURE
SYMPTOM: Mode door motor and/or air mix door motor does not operate normally.
Perform diagnostic procedure for LAN system circuit. Refer to LAN System Circuit.