Automatic Air Conditioning
MODE DOOR MOTOR
System Description
SYSTEM DESCRIPTION
Component Parts
- A/C auto amp.
- A/C and AV switch assembly
- Mode door motor (front)
- PBR (built into mode door motor)
- In-vehicle sensor
- Ambient sensor
- Optical sensor
- Intake sensor
System Operation
The mode door position (vent, B/L, foot, D/F, and defrost) is set by the A/C auto amp. by means of the mode door motor (front). When a mode door position is selected on the A/C auto amp., voltage is applied to one circuit of the mode door motor (front) while ground is applied to the other circuit, causing the mode door motor (front) to rotate. The direction of rotation is determined by which circuit has voltage applied to it, and which one has ground applied to it. The A/C auto amp. monitors the mode door position by measuring the voltage signal on the PBR circuit.
In AUTO mode the mode door position is set by the A/C auto amp. which determines the proper position based on inputs from the in-vehicle sensor, ambient sensor, optical sensor, intake sensor, and the temperature selected by the driver or passenger.
Mode Door Control Specification
COMPONENT DESCRIPTION
Mode Door Motor (Front)
The mode door motor (front) is attached to the heater & cooling unit assembly. It rotates so that air is discharged from the outlet as indicated by the A/C auto amp. Motor rotation is conveyed to a link which activates the mode door.
Mode Door Motor (Front) Component Function Check
INSPECTION FLOW
1. CONFIRM SYMPTOM BY PERFORMING OPERATIONAL CHECK - DISCHARGE AIR
1.Press mode switch four times and then press the (DEF) switch. Each position indicator should change shape (on display).
2.Confirm that discharge air comes out according to the air distribution table. Discharge Air Flow (Front).
NOTE:
Confirm that the compressor clutch is engaged (visual inspection) and intake door position is at FRESH
when FOOT (), DEF () or D/F () is selected.
Is the inspection result normal?
YES- Inspection End.
NO- Go to diagnosis procedure. Refer to .
Mode Door Motor (Front) Diagnosis Procedure
Regarding Wiring Diagram information, Automatic Air Conditioning.
- Air outlet does not change.
- Mode door motor does not operate normally.
1. CHECK MODE DOOR MOTOR POSITION BALANCED RESISTOR (PBR) FEEDBACK VOLTAGE
1.Turn ignition switch ON.
2.Using CONSULT, check "MODE FDBCK" in "DATA MONITOR" mode in "HVAC". CONSULT Function (HVAC).
3.Observe "MODE FDBCK" voltage while cycling A/C auto amp. mode switch through all modes.
Is the inspection result normal?
YES- - Mode door motor is OK.
- Inspect mode door for mechanical failure. Mode Door Motor.
NO- GO TO 2.
2. CHECK MODE DOOR MOTOR CIRCUITS FOR OPEN AND SHORT TO GROUND
1.Turn ignition switch OFF.
2.Disconnect the A/C auto amp. harness connector M49 and the mode door motor harness connector
M142.
3.Check continuity between A/C auto amp. harness connector M49 terminals 19, 20 and the mode door motor harness connector M142 terminals 5, 6.
4.Check continuity between A/C auto amp. harness connector M49 terminals 19, 20 and ground.
Is the inspection result normal?
YES- GO TO 3.
NO- Repair or replace harness as necessary.
3. CHECK A/C AUTO AMP. FOR MODE DOOR MOTOR POWER AND GROUND
1.Reconnect A/C auto amp. harness connector.
2.Turn ignition switch ON.
3.Press the mode switch to the D/F () mode.
4.Check voltage between A/C auto amp. harness connector M49 terminal 19 and terminal 20 while pressing the mode switch to the VENT (), and then the B/L () mode.
Is the inspection result normal?
YES- GO TO 4.
NO- Replace A/C auto amp. Service and Repair.
4. CHECK MODE DOOR MOTOR PBR CIRCUITS FOR OPEN AND SHORT TO GROUND
1.Turn ignition switch OFF.
2.Disconnect the A/C auto amp. harness connectors.
3.Check continuity between A/C auto amp. harness connector M49 terminal 3, and M50 terminal 28 and the mode door motor harness connector M142 terminals 2, 3.
4.Check continuity between A/C auto amp. harness connector M49 terminal 3, M50 terminal 28 and ground.
Is the inspection result normal?
YES- GO TO 5.
NO- Repair or replace harness as necessary.
5. CHECK PBR FEEDBACK SIGNAL CIRCUIT FOR OPEN AND SHORT TO GROUND
1.Check continuity between A/C auto amp. harness connector M49 terminal 7 and mode door motor harness connector M142 terminal 4.
2.Check continuity between A/C auto amp. harness connector M49 terminal 7 and ground.
Is the inspection result normal?
YES- GO TO 6.
NO- Repair or replace harness as necessary.
6. CHECK A/C AUTO AMP. FOR 5 VOLT REFERENCE (VREF), VREF RETURN, AND FEEDBACK SIGNAL
1.Reconnect A/C auto amp. harness connectors.
2.Turn ignition switch ON.
3.Check voltage between A/C auto amp. harness connector M49 terminal 3, and M50 terminal 28.
4.Check voltage between A/C auto amp. harness connector M49 terminal 7 and ground.
Is the inspection result normal?
YES- GO TO 7.
NO- Replace A/C auto amp.. Service and Repair.
7. CHECK A/C AUTO AMP. FOR FEEDBACK SIGNAL
1.Reconnect the mode door motor harness connector M142.
2.Check voltage between A/C auto amp. harness connector M49 terminal 7 and ground.
Is the inspection result normal?
YES- Inspect mode door for binding or mechanical failure. If mode door moves freely, replace A/C auto amp.. Service and Repair.
NO- Replace the mode door motor. Mode Door Motor.