2006 INFINITI QX56 ignition

TROUBLE DIAGNOSISATC-63
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Revision: November 2009 2006 QX56
1. CHECK POWER SUPPLY CIRCUITS FOR FRONT AIR CONTROL
1. Disconnect front air control connector.
2. Check voltage between front air control harness connector M49 terminals 14 and 22, and ground.
OK or NG
OK >> GO TO 2.
NG >> Check 10A fuses [Nos. 8 and 19, located in the fuse block (J/B)]. Refer to PG-76, "
FUSE BLOCK-
JUNCTION BOX (J/B)" .

If fuses are OK, check harness for open circuit. Repair or replace as necessary.

If fuses are NG, replace fuse and check harness for short circuit. Repair or replace as neces-
sary.
2. CHECK GROUND CIRCUIT FOR FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Check continuity between front air control harness connector M49 terminal 1 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-144, "FRONT
AIR CONTROL" .
NG >> Repair harness or connector.
Terminals Ignition switch position
(+)
(-) OFF ACC ON
Front air
control
connector Terminal No.
M49 14 GroundApprox. 0V Approx. 0V
Battery
voltage
M49 22 Battery
voltage Battery
voltage Battery
voltage
WJIA0415E
1 - Ground : Continuity should exist.
WJIA1351E

ATC-66
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
COMPONENT DESCRIPTION
Mode Door Motor
The mode door motor is attached to the heater & cooling unit. 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.
DIAGNOSTIC PROCEDURE FOR MODE DOOR MOTOR
1. CHECK FRONT AIR CONTROL FOR POWER AND GROUND
1. Turn ignition switch ON.
2. Press the mode switch to the B/L ( ) mode.
3. Check voltage between front air control harness connector M49 terminal 5 and terminal 6 while pressing the mode switch to the
floor ( ) mode.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. CHECK MODE 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 5, 6 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-144, "FRONT
AIR CONTROL" .
NG >> Repair or replace harness as necessary.
WJIA0587E
Connector Terminals
Condition Voltage
(Approx.)
(+) (-)
Front air control: M49 6 5 Press
mode
switch Battery
voltage
WJIA1727E
5 - Ground : Continuity should not exist.
6 - Ground : Continuity should not exist.
WJIA1734E

TROUBLE DIAGNOSISATC-67
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Revision: November 2009 2006 QX56
3. CHECK FRONT AIR CONTROL FOR GROUND AND POWER
1. Press the mode switch to the D/F ( ) mode.
2. Check voltage between front air control harness connector M49 terminal 5 and terminal 6 while pressing the mode switch to the
vent ( ) mode.
OK or NG
OK >> GO TO 4.
NG >> Replace front air control. Refer to ATC-144, "
FRONT AIR CONTROL" .
4. CHECK MODE 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 5 and terminal 6.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5. CHECK MODE DOOR MOTOR CIRCUITS FOR OPEN
1. Disconnect the mode door motor harness connector.
2. Check continuity between front air control harness connector M49 terminal 5, 6 and the mode door motor harness connector
terminal 5, 6.
OK or NG
OK >> Replace mode door motor. Refer to ATC-161, "Removal
and Installation" .
NG >> Repair or replace harness as necessary.
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.
Connector Terminals
Condition Voltage
(Approx.)
(+) (-)
Front air control: M49 5 6 Press
mode
switch Battery
voltage
WJIA1742E
Continuity should exist.
WJIA1728E
5 - 5 : Continuity should exist.
6 - 6 : Continuity should exist.
LJIA0027E
Connector Te r m i n a l s
Voltage
(Approx.)
(+) (-)
Front air control: M49 2 15 5V
WJIA1729E

ATC-68
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
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 mode door motor harness connector.
2. Check continuity between mode door motor harness connector M142 (B) terminal 3, 1 and front air control harness connector
M49 (A) terminal 2, 15.
OK or NG
OK >> Replace mode door motor. Refer to ATC-161, "Removal
and Installation" .
NG >> Repair or replace harness as necessary.
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 M49 terminal 16 and ground while cycling mode switch through all
modes.
OK or NG
OK >> GO TO 12.
NG >> GO TO 11. Continuity should not exist.
WJIA1730E
Continuity should exist.
WJIA1731E
2 - 3
: Continuity should exist.
15 - 1 : Continuity should exist.
WJIA1732E
Voltage : Approx. 1V - 4.5V
LJIA0032E

TROUBLE DIAGNOSISATC-69
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Revision: November 2009 2006 QX56
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 M49 terminal 16 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 mode door motor harness connector and front air control harness connector.
3. Check continuity between mode door motor harness connector M142 terminal 2 and front air control harness connector M49 ter-
minal 16.
OK or NG
OK >> Replace mode door motor. Refer to ATC-161, "Removal
and Installation" .
NG >> Repair or replace harness as necessary. Continuity should not exist.
WJIA1733E
Continuity should exist.
LJIA0034E

ATC-72
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
COMPONENT DESCRIPTION
Air Mix Door Motors
The driver (1) and front passenger (2) air mix door motors are
attached to the front heater & cooling unit assembly. The rear air mix
door motor is attached to the rear heater & cooling unit. These
motors rotate so that the air mix door is opened or closed to a posi-
tion set by the front (or rear) air control. Motor rotation is then con-
veyed through a shaft and the air mix door position is then fed back
to the front air control by the PBR built into the air mix door motors.
DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR (DRIVER)
1. CHECK FRONT AIR CONTROL FOR POWER AND GROUND
1. Turn ignition switch ON.
2. Rotate temperature control dial (driver) to 32° C (90°F).
3. Check voltage between front air control harness connector M49 terminal 3 and terminal 4 while rotating temperature control dial
(driver) to 16 °C (60 °F).
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. CHECK AIR MIX DOOR MOTOR (DRIVER) 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 3, 4 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-144, "FRONT
AIR CONTROL" .
NG >> Repair or replace harness as necessary.
WJIA2309E
WJIA1245E
Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
Front air control: M49 3 4 Rotate temp
control dial Battery
voltage
WJIA1735E
3 - Ground : Continuity should not exist.
4 - Ground : Continuity should not exist.
WJIA1736E

TROUBLE DIAGNOSISATC-73
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Revision: November 2009 2006 QX56
3. CHECK FRONT AIR CONTROL FOR POWER AND GROUND
1. Turn ignition switch ON.
2. Rotate temperature control dial (driver) to 32 °C (90 °F).
3. Check voltage between front air control harness connector M49 terminal 3 and terminal 4 while rotating temperature control dial
(driver) to 16 °C (60 °F).
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 (DRIVER) 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 3 and terminal 4.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5. CHECK AIR MIX DOOR MOTOR (DRIVER) CIRCUITS FOR OPEN
1. Disconnect the air mix door motor (driver) harness connector.
2. Check continuity between front air control harness connector M49 terminal 3, 4 and the air mix door motor (driver) harness
connector M147 terminal 1, 6.
OK or NG
OK >> Replace air mix door motor (driver). Refer to ATC-163,
"FRONT AIR MIX DOOR MOTOR (PASSENGER)" .
NG >> Repair or replace harness as necessary.
Connector Terminals
Condition Voltage
(Approx.)
(+) (-)
Front air control: M49 4 3
Rotate temp
control dial Battery
voltage
WJIA1737E
Continuity should exist.
WJIA1738E
3 - 1 : Continuity should exist.
4 - 6 : Continuity should exist.
WJIA0588E

ATC-74
TROUBLE DIAGNOSIS
Revision: November 20092006 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 (driver) harness connector.
2. Check continuity between air mix door motor (driver) harness connector M147 (B) terminal 3, 2 and front air control harness
connector M49 (A) terminal 2, 15.
OK or NG
OK >> Replace air mix door motor (driver). Refer to ATC-163,
"FRONT AIR MIX DOOR MOTOR (PASSENGER)" .
NG >> Repair or replace harness as necessary.
Connector Terminals
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.
WJIA1777E