2005 INFINITI QX4 ignition

TROUBLE DIAGNOSIS
ATC-79
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: October 20052005 QX56
12. CHECK PBR FEEDBACK CIRCUIT FOR OPEN
1. Turn ignition switch OFF.
2. Disconnect the air mix door motor (passenger) harness connec-
tor and front air control harness connector.
3. Check continuity between air mix door motor (passenger) har-
ness connector M143 terminal 4 and front air control harness
connector M50 terminal 41.
OK or NG
OK >> Replace air mix door motor (passenger). Refer to AT C -
167, "FRONT AIR MIX DOOR MOTOR (PASSENGER)"
.
NG >> Repair or replace harness as necessary.
DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR (REAR)
1. CHECK FRONT AIR CONTROL FOR POWER AND GROUND
1. Turn ignition switch ON.
2. Rotate temperature control dial (rear) to maximum heat.
3. Check voltage between front air control harness connector M50
terminal 27 and terminal 28 while rotating temperature control
dial (rear) to maximum cold.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. CHECK AIR MIX DOOR MOTOR (REAR) 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
M50 terminal 27, 28 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-147, "FRONT
AIR CONTROL" .
NG >> Repair or replace harness as necessary.Continuity should exist.
WJIA0550E
ConnectorTe r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
Front air control:
M5027 28Rotate temp
control dialBattery
voltage
WJIA1744E
27 - Ground : Continuity should not exist.
28 - Ground : Continuity should not exist.
WJIA1745E

ATC-80
TROUBLE DIAGNOSIS
Revision: October 20052005 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-147, "
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-167,
"REAR AIR MIX DOOR MOTOR" .
NG >> Repair or replace harness as necessary.
ConnectorTe r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
Front air control:
M5028 27Rotate temp
control dialBattery
voltage
WJIA1746E
Continuity should exist.
WJIA1747E
27 - 1 : Continuity should exist.
28 - 6 : Continuity should exist.
LJIA0049E

TROUBLE DIAGNOSIS
ATC-81
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: October 20052005 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-147, "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-167,
"REAR AIR MIX DOOR MOTOR" .
NG >> Repair or replace harness as necessary.
ConnectorTe 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

ATC-82
TROUBLE DIAGNOSIS
Revision: October 20052005 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-147, "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-167,
"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

TROUBLE DIAGNOSIS
ATC-85
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: October 20052005 QX56
COMPONENT DESCRIPTION
Intake door motor
The intake door motor is attached to the intake unit. 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-147, "FRONT
AIR CONTROL" .
NG >> Repair or replace harness as necessary.
WJIA0552E
ConnectorTerminals
Condition Voltage
(Approx.)
(+) (-)
Front air control:
M497 8Self-diagnostic
modeBattery
voltage
WJIA1757E
7 - Ground : Continuity should not exist.
8 - Ground : Continuity should not exist.
WJIA1758E

ATC-86
TROUBLE DIAGNOSIS
Revision: October 20052005 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-147, "
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-164, "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-164, "Removal
and Installation" .
NG >> Repair or replace harness as necessary.
ConnectorTerminals
Condition Voltage
(Approx.)
(+) (-)
Front air control:
M498 7Self-diagnostic
modeBattery
voltage
WJIA1759E
Continuity should exist.
WJIA1760E
1 - 7 : Continuity should exist.
6 - 8 : Continuity should exist.
WJIA0591E

TROUBLE DIAGNOSIS
ATC-89
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: October 20052005 QX56
DIAGNOSTIC PROCEDURE FOR DEFROSTER DOOR MOTOR
1. CHECK FRONT AIR CONTROL FOR POWER AND GROUND
1. Turn ignition switch ON.
2. Press the defroster switch ( ).
3. Check voltage between front air control harness connector M49
terminal 20 and terminal 19 and press the defroster switch ( )
again.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. CHECK DEFROSTER 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 19, 20 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-147, "FRONT
AIR CONTROL" .
NG >> Repair or replace harness as necessary.
3. CHECK FRONT AIR CONTROL FOR GROUND AND POWER
1. Press the defroster switch ( ).
2. Check voltage between front air control harness connector M49
terminal 19 and terminal 20 and press the defroster switch ( )
again.
OK or NG
OK >> GO TO 4.
NG >> Replace front air control. Refer to ATC-147, "
FRONT AIR CONTROL" .
ConnectorTerminals
Condition Voltage
(Approx.)
(+) (-)
Front air control:
M4920 19Press
defroster
switchBattery
voltage
WJIA1765E
19 - Ground : Continuity should not exist.
20 - Ground : Continuity should not exist.
WJIA1766E
ConnectorTerminals
Condition Voltage
(Approx.)
(+) (-)
Front air control:
M4919 20Press
defroster
switchBattery
voltage
WJIA1767E

ATC-90
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
4. CHECK DEFROSTER 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 19 and terminal 20.
OK or NG6
OK >> GO TO 6.
NG >> GO TO 5.
5. CHECK DEFROSTER DOOR MOTOR CIRCUITS FOR OPEN
1. Disconnect the defroster door motor harness connector.
2. Check continuity between front air control harness connector
M49 terminal 19, 20 and the defroster door motor harness con-
nector terminal 1, 6.
OK or NG
OK >> Replace defroster door motor. Refer to ATC-163,
"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.
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-147, "FRONT
AIR CONTROL" .
NG >> Repair or replace harness as necessary.Continuity should exist.
WJIA1773E
19 - 1 : Continuity should exist.
20 - 6 : Continuity should exist.
WJIA0553E
ConnectorTe r m i n a l s
Voltage
(Approx.)
(+) (-)
Front air control: M49 2 15 5V
WJIA1729E
Continuity should not exist.
WJIA1730E