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ATC-80
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
3. CHECK FRONT AIR CONTROL FOR POWER AND GROUND
1. Turn ignition switch ON.
2. Rotate temperature control dial (rear) to maximum cold.
3. Check voltage between front air control harness connector M50 terminal 27 and terminal 28 while rotating temperature control
dial (rear) to maximum heat.
OK or NG
OK >> GO TO 4.
NG >> Replace front air control. Refer to ATC-144, "
FRONT AIR CONTROL" .
4. CHECK AIR MIX DOOR MOTOR (REAR) CIRCUITS FOR OPEN
1. Turn ignition switch OFF.
2. Disconnect the front air control harness connector.
3. Check continuity between front air control harness connector M50 terminal 27 and terminal 28.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5. CHECK AIR MIX DOOR MOTOR (REAR) CIRCUITS FOR OPEN
1. Disconnect the air mix door motor (rear) harness connector.
2. Check continuity between front air control harness connector M50 terminal 27, 28 and the air mix door motor (rear) harness
connector B155 terminal 1, 6.
OK or NG
OK >> Replace air mix door motor (rear). Refer to ATC-163,
"REAR AIR MIX DOOR MOTOR" .
NG >> Repair or replace harness as necessary.
Connector Terminals
Condition Voltage
(Approx.)
(+) (-)
Front air control: M50 28 27
Rotate temp
control dial Battery
voltage
WJIA1746E
Continuity should exist.
WJIA1747E
27 - 1 : Continuity should exist.
28 - 6 : Continuity should exist.
LJIA0049E
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TROUBLE DIAGNOSISATC-81
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Revision: November 2009 2006 QX56
6. CHECK FRONT AIR CONTROL FOR PBR POWER AND GROUND
1. Reconnect front air control harness connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M49 terminal 2 and terminal 15.
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
7. CHECK PBR REFERENCE VOLTAGE CIRCUIT FOR SHORT TO GROUND
1. Turn ignition switch OFF.
2. Disconnect the front air control harness connector.
3. Check continuity between front air control harness connector M49 terminal 2 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-144, "FRONT
AIR CONTROL" .
NG >> Repair or replace harness as necessary.
8. CHECK PBR REFERENCE VOLTAGE AND GROUND CIRCUITS
1. Turn ignition switch OFF.
2. Disconnect the front air control harness connector.
3. Check continuity between front air control harness connector M49 terminal 2 and terminal 15.
OK or NG
OK >> GO TO 10.
NG >> GO TO 9.
9. CHECK PBR REFERENCE VOLTAGE CIRCUIT FOR OPEN
1. Disconnect the air mix door motor (rear) harness connector.
2. Check continuity between air mix door motor (rear) harness con- nector B155 (B) terminal 3, 2 and front air control harness con-
nector M49 (A) terminal 2, 15.
OK or NG
OK >> Replace air mix door motor (rear). Refer to ATC-163,
"REAR AIR MIX DOOR MOTOR" .
NG >> Repair or replace harness as necessary.
Connector Te r m i n a l s
Voltage
(Approx.)
(+) (-)
Front air control: M49 2 15 5V
WJIA1729E
Continuity should not exist.
WJIA1730E
Continuity should exist.
WJIA1731E
2 - 3 : Continuity should exist.
15 - 2 : Continuity should exist.
WJIA1748E
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ATC-82
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
10. CHECK PBR FEEDBACK VOLTAGE
1. Reconnect the front air control harness connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M50 terminal 42 and ground while rotating temperature control dial
(rear) from maximum cold to maximum heat.
OK or NG
OK >> GO TO 12.
NG >> GO TO 11.
11 . CHECK PBR FEEDBACK SIGNAL CIRCUIT FOR SHORT TO GROUND
1. Turn ignition switch OFF.
2. Disconnect front air control harness connector.
3. Check continuity between front air control harness connector M50 terminal 42 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-144, "FRONT
AIR CONTROL" .
NG >> Repair or replace harness as necessary.
12. CHECK PBR FEEDBACK CIRCUIT FOR OPEN
1. Turn ignition switch OFF.
2. Disconnect the air mix door motor (rear) harness connector and front air control harness connector.
3. Check continuity between air mix door motor (rear) harness con- nector B155 terminal 4 and front air control harness connector
M50 terminal 42.
OK or NG
OK >> Replace air mix door motor (rear). Refer to ATC-163,
"REAR AIR MIX DOOR MOTOR" .
NG >> Repair or replace harness as necessary. Voltage : Approx. 1V - 4.5V
LJIA0053E
Continuity should not exist.
WJIA1749E
Continuity should exist.
LJIA0054E
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TROUBLE DIAGNOSISATC-83
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AT C
Revision: November 2009 2006 QX56
Intake Door Motor CircuitEJS003XQ
SYMPTOM:
Intake door does not change.
Intake door motor does not operate normally.
INSPECTION FLOW
*1ATC-58, "Operational Check (Front)"*2ATC-56, "A/C System Self-diagno-
sis Function"
*3 ATC-57, "SELF-DIAGNOSIS CODE
CHART"
WJIA1440E
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ATC-84
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
SYSTEM DESCRIPTION
Component Parts
Intake door control system components are:
Front air control
Intake door motor
In-vehicle sensor
Ambient sensor
Optical sensor
Intake sensor
System Operation
The intake door control determines the intake door position based on the position of the recirculation switch.
When the recirculation switch is depressed the intake door motor rotates closing off the fresh air inlet and
recirculating the cabin air. If the recirculation switch is depressed again, the intake door motor rotates in the
opposite direction, again allowing fresh air into the cabin.
In the AUTO mode, the front air control determines the intake door position based on the ambient tempera-
ture, the intake air temperature and the in-vehicle temperature. When the DEF, D/F, FLOOR or OFF switches
are pushed, the front air control sets the intake door at the fresh position.
Intake Door Control Specification
WJIA1915E
WJIA0436E
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TROUBLE DIAGNOSISATC-85
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Revision: November 2009 2006 QX56
COMPONENT DESCRIPTION
Intake door motor
The intake door motor is attached to the intake unit assembly. It
rotates so that air is drawn from inlets set by the front air control.
Motor rotation is conveyed to a lever which activates the intake door.
DIAGNOSTIC PROCEDURE FOR INTAKE DOOR MOTOR
1. CHECK FRONT AIR CONTROL FOR POWER AND GROUND
1. Turn ignition switch ON.
2. Check voltage between front air control harness connector M49 terminal 7 and terminal 8 while placing the HVAC system into
self-diagnostic mode.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. CHECK INTAKE DOOR MOTOR CIRCUITS FOR SHORT TO GROUND
1. Turn ignition switch OFF.
2. Disconnect the front air control harness connector.
3. Check continuity between front air control harness connector M49 terminal 7, 8 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-144, "FRONT
AIR CONTROL" .
NG >> Repair or replace harness as necessary.
WJIA0552E
Connector Terminals
Condition Voltage
(Approx.)
(+) (-)
Front air control: M49 7 8
Self-diagnostic
mode Battery
voltage
WJIA1757E
7 - Ground : Continuity should not exist.
8 - Ground : Continuity should not exist.
WJIA1758E
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ATC-86
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
3. CHECK FRONT AIR CONTROL FOR GROUND AND POWER
1. Press the BACK button to back out of self-diagnostic mode.
2. Check voltage between front air control harness connector M49 terminal 7 and terminal 8 while placing the HVAC system into
self-diagnostic mode.
OK or NG
OK >> GO TO 4.
NG >> Replace front air control. Refer to ATC-144, "
FRONT AIR CONTROL" .
4. CHECK INTAKE DOOR MOTOR AND CIRCUITS FOR OPEN
1. Turn ignition switch OFF.
2. Disconnect the front air control harness connector.
3. Check continuity between front air control harness connector M49 terminal 7 and terminal 8.
OK or NG
OK >> Replace intake door motor. Refer to ATC-160, "Removal
and Installation" .
NG >> GO TO 5.
5. CHECK INTAKE DOOR MOTOR CIRCUITS FOR OPEN
1. Disconnect the intake door motor harness connector.
2. Check continuity between front air control harness connector M49 terminal 7, 8 and the intake door motor harness connector
M58 terminal 1, 6.
OK or NG
OK >> Replace intake door motor. Refer to ATC-160, "Removal
and Installation" .
NG >> Repair or replace harness as necessary.
Connector Terminals
Condition Voltage
(Approx.)
(+) (-)
Front air control: M49 8 7 Self-diagnostic
mode Battery
voltage
WJIA1759E
Continuity should exist.
WJIA1760E
1 - 7 : Continuity should exist.
6 - 8 : Continuity should exist.
WJIA0591E
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TROUBLE DIAGNOSISATC-87
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M A
B
AT C
Revision: November 2009 2006 QX56
Defroster Door Motor CircuitEJS003XR
SYMPTOM:
Defroster door does not change.
Defroster door motor does not operate normally.
INSPECTION FLOW
*1AT C - 5 8 , "Operational Check
(Front)"*2
ATC-87, "Defroster Door Motor Circuit"*3ATC-144, "FRONT AIR CONTROL"
*4 ATC-159, "DEFROSTER DOOR
MOTOR"
WJIA1921E