Description

SYSTEM DESCRIPTION

Component Parts

Mode door control system components are: • Front air control

• Mode door motor (LCU)

System Operation

The front air control receives user inputs through its various dials and switches. The front air control sends air mix door, mode door and intake door opening angle data to the air mix door motor LCU, mode door motor LCU and intake door motor LCU.

The air mix door motor, mode door motor and intake door motor read 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.

Diagnosis Procedure

SYMPTOM: Mode door motor and/or air mix door motor does not operate normally.

Perform diagnostic procedure for LAN system circuit. Refer to HAC-115, "Diagnosis Procedure".

SYMPTOM: • Air outlet does not change.

• Mode door motor does not operate normally.

INSPECTION FLOW

1. CONFIRM SYMPTOM BY PERFORMING OPERATION CHECK - DISCHARGE AIR

1. Press each of the four mode position switches and then press the (DEF) switch. Each position indicator should illuminate.

2. Confirm that discharge air comes out according to the air distribution table. Refer to HAC-107, "System Description".

NOTE: Confirm that the compressor clutch is engaged (visual inspection and intake door position is at (FRESH) when (DEF) or (D/F) is selected.

Can a symptom be duplicated? YES >> GO TO 3

N0 >> GO TO 2

2. PERFORM COMPLETE OPERATIONAL CHECK

Perform a complete operational check and check for any symptoms. Refer to HAC-102, "Operational Check".

Can a symptom be duplicated? YES >> Refer to HAC-155, "Symptom Matrix Chart".

NO >> System OK.

3. CHECK FOR SERVICE BULLETINS

Check for any service bulletins.

>> GO TO 4

4. CHECK LAN SYSTEM CIRCUIT

Perform diagnostic procedure for the LAN system. Refer to HAC-115, "Diagnosis Procedure".

Is the inspection result normal? YES >> GO TO 5

NO >> Repair as necessary.

5. CHECK MODE DOOR OPERATION

Check and verify mode door mechanism for smooth operation in each mode.

Is the inspection result normal? YES >> GO TO 6

NO >> Repair as necessary.

6. CHECK AIR MIX DOOR MOTOR PBR CIRCUIT

Perform diagnostic procedure for the intake sensor circuit. Refer to HAC-122, "Diagnosis Procedure".

Is the inspection result normal? YES >> GO TO 7

NO >> Repair as necessary.

7. RECHECK FOR SYMPTOMS

Perform a complete operational check and check for any symptoms. Refer to HAC-102, "Operational Check".

Does another symptom exist? YES >> Repair as necessary.

NO >> Replace front air control. Refer to VTL-8, "Removal and Installation".

DIAGNOSIS PROCEDURE FOR MODE DOOR MOTOR

SYMPTOM: Mode door motor does not operate normally.

Perform diagnosis procedure. Refer to HAC-115, "Diagnosis Procedure".