Automatic Air Conditioning
MODE DOOR MOTOR
System Description
SYSTEM DESCRIPTION
Component Parts
- Front air control
- Mode door motor
- 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 front air control by means of the mode door motor. When a mode door position is selected on the front air control, voltage is applied to one circuit of the mode door motor while ground is applied to the other circuit, causing the mode door motor 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 front air control 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 front air control 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
The mode door motor is attached to the heater & cooling unit assembly. It rotates so that air is discharged from the outlet as indicated by the front air control. Motor rotation is conveyed to a link which activates the mode door.
Mode Door Motor Component Function Check
INSPECTION FLOW
1. CONFIRM SYMPTOM BY PERFORMING OPERATIONAL CHECK - DISCHARGE AIR
1.Press each mode switch and press the (DEF) switch. Each position indicator should illuminate.
2.Confirm that discharge air comes out according to the air distribution table. Discharge Air Flow.
NOTE:
Confirm that the compressor clutch is engaged (visual inspection) and intake door position is at FRESH
when DEF () or D/F () is selected.
Is the inspection result normal?
YES- Inspection End.
NO- Go to diagnosis procedure. .
Mode Door Motor 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 front air control 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 front air control harness connector M49 (A) and the mode door motor harness connector M142 (B).
3.Check continuity between front air control harness connector
M49 (A) terminals 19, 20 and the mode door motor harness connector M142 (B) terminals 5, 6.
4.Check continuity between front air control 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 FRONT AIR CONTROL FOR MODE DOOR MOTOR POWER AND GROUND
1.Reconnect front air control harness connector.
2.Turn ignition switch ON.
3.Press the mode switch to the D/F () mode.
4.Check voltage between front air control 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 front air control. Service and Repair.
4. CHECK MODE DOOR MOTOR PBR CIRCUITS FOR OPEN AND SHORT TO GROUND
1.Turn ignition switch OFF.
2.Disconnect the front air control harness connectors.
3.Check continuity between front air control harness connector
M49 (C) terminal 3, and M50 (A) terminal 28 and the mode door motor harness connector M142 (B) terminals 1, 3.
4.Check continuity between front air control harness connector
M49 (C) terminal 3, M50 (A) 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 front air control harness connector
M49 (A) terminal 7 and mode door motor harness connector
M142 (B) terminal 2.
2.Check continuity between front air control 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 FRONT AIR CONTROL FOR 5 VOLT REFERENCE (VREF), VREF RETURN, AND FEEDBACK
SIGNAL
1.Reconnect front air control harness connectors.
2.Turn ignition switch ON.
3.Check voltage between front air control harness connector M49
(B) terminal 3, and M50 (A) terminal 28.
4.Check voltage between front air control harness connector M49
terminal 7 and ground.
Is the inspection result normal?
YES- GO TO 7.
NO- Replace front air control. Service and Repair.
7. CHECK FRONT AIR CONTROL FOR FEEDBACK SIGNAL
1.Reconnect the mode door motor harness connector M142.
2.Check voltage between front air control 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 front air control. Service and Repair.
NO- Replace the mode door motor. Mode Door Motor.