INFINITI QX4 2005 Factory Service Manual

ATC-106
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
6. CHECK REAR BLOWER MOTOR RELAY (COIL SIDE) POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect fuse block (J/B) connector.
3. Turn ignition switch ON.
4. Set rear blower switch (front) to any position except OFF, REAR,
or 4 - speed.
5. Check voltage between fuse block (J/B) harness connector M39
terminal 3Q (W/L) and ground.
OK or NG
OK >> GO TO 7.
NG >> GO TO 20.
7. CHECK REAR BLOWER MOTOR RELAY (COIL SIDE) GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check continuity between fuse block (J/B) harness connector
M3 terminal 7N (B) and ground.
OK or NG
OK >> Replace fuse block (J/B).
NG >> Repair harness or connector.
8. REPLACE FUSE
Refer to PG-76, "
FUSE BLOCK-JUNCTION BOX(J/B)"
Fuse should not open when rear blower motor is activated.
OK or NG
OK >> Inspection End.
NG >> GO TO 9.
9. CHECK REAR BLOWER MOTOR POWER SUPPLY CIRCUIT FOR SHORT
1. Turn ignition switch OFF.
2. Disconnect battery cables and rear blower motor connector.
3. Check continuity between rear blower motor harness connector
B134 terminal 2 (L/R) and ground.
OK or NG
OK >> Check rear blower motor. Refer to ATC-100, "Front
Blower Motor" .
NG >> Repair harness or connector. 3Q - Ground : Battery voltage.
LJIA0101E
7N - Ground : Continuity should exist.
WJIA0597E
2 - Ground : Continuity should not exist.
WJIA0598E

TROUBLE DIAGNOSIS
ATC-107
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: October 20052005 QX56
10. CHECK REAR BLOWER MOTOR RELAY (SWITCH SIDE) POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect fuse block (J/B) and rear blower motor connectors.
3. Check continuity between fuse block (J/B) harness connector
M3 terminal 3N (SB) and 8N (L/R) and rear blower motor har-
ness connector B134 terminal 2 (L/R).
OK or NG
OK >> GO TO 20.
NG >> Repair harness or connector.
11 . CHECK REAR BLOWER MOTOR
Refer to ATC-100, "
Front Blower Motor" .
OK or NG
OK >> GO TO 12.
NG >> Replace rear blower motor. refer to ATC-153, "
REAR BLOWER MOTOR"
12. CHECK REAR BLOWER SWITCH (FRONT)
Refer to AT C - 11 0 , "
Rear Blower Switch (Front)" .
OK or NG
OK >> GO TO 15.
NG >> Replace rear blower switch (front). Refer to ATC-147, "
FRONT AIR CONTROL"
13. CHECK REAR BLOWER MOTOR RESISTOR
Refer to AT C - 111 , "
Rear Blower Motor Resistor" .
OK or NG
OK >> GO TO 14.
NG >> Replace rear blower motor resistor. Refer to ATC-169, "
REAR BLOWER MOTOR RESISTOR"
14. CHECK REAR BLOWER SWITCH (FRONT) CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect rear blower switch (front) M52.
3. Turn ignition switch ON.
4. Reconnect rear blower motor resistor harness connector B133.
5. Check voltage between each rear blower switch (front) connec-
tor M52 terminals 3 (LG), 7 (W/L), and 8 (G), and ground.
OK or NG
OK >> GO TO 17.
NG >> GO TO 16.3N, 8N - 2 : Continuity should exist.
WJIA0599E
Te r m i n a l N o .
Voltage
(+) (-)
3
Ground Approx. 12V 7
8
LJIA0108E

ATC-108
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
15. CHECK REAR BLOWER MOTOR GROUND CIRCUIT TO REAR BLOWER MOTOR RESISTOR
1. Turn ignition switch OFF.
2. Disconnect rear blower motor (A) and rear blower motor resistor
(B) connectors.
3. Check continuity between rear blower motor connector B134 (A)
terminal 1 (L/B) and rear blower motor resistor harness connec-
tor B133 (B) terminal 3 (L/B).
4. Check continuity between rear blower motor connector B134 (A)
terminal 1 (L/B) and ground.
OK or NG
OK >> GO TO 16.
NG >> Repair harness or connector.
16. CHECK REAR BLOWER SWITCH (FRONT) CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect rear blower motor resistor (B) connector.
3. Check continuity between rear blower switch (front) connector
M52 (A) terminals 3 (LG), 7 (W/L), and 8 (G), and rear blower
motor resistor connector B133 (B) terminals 1 (LG), 4 (W/L), and
2 (G).
OK or NG
OK >> Inspection End.
NG >> Repair harness or connector.
17. CHECK REAR BLOWER SWITCH (FRONT) CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect rear blower switch (rear) connectors.
3. Check continuity between rear blower switch (front) connector
M52 terminals 3 (LG), 5 (L/B), 7 (W/L), and 8 (G), and rear
blower switch (rear) connector R208 terminals 9 (LG), 6 (L/B), 8
(W/L), and 7 (G).
OK or NG
OK >> GO TO 18.
NG >> Repair harness or connector.1 - 3 : Continuity should exist.
1 - Ground : Continuity should not exist.
WJIA1916E
Te r m i n a l N o .
Continuity
Rear blower switch (front) Rear blower motor resistor
31
Should exist 74
82
WJIA1651E
Te r m i n a l N o .
Continuity
Rear blower switch (front) Rear blower switch (rear)
39
Should exist 56
78
87
LJ IA0110E

TROUBLE DIAGNOSIS
ATC-109
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: October 20052005 QX56
18. CHECK REAR BLOWER SWITCH (FRONT)
Refer to AT C - 11 0 , "
Rear Blower Switch (Front)" .
OK or NG
OK >> GO TO 19.
NG >> Replace rear blower switch (front). Refer to ATC-147, "
FRONT AIR CONTROL"
19. CHECK REAR BLOWER SWITCH (REAR)
Refer to AT C - 11 0 , "
Rear Blower Switch (Rear)" .
OK or NG
OK >> Inspection End.
NG >> Replace rear blower switch (rear). Refer to ATC-147, "
REAR AIR CONTROL"
20. CHECK CIRCUIT BETWEEN FRONT AIR CONTROL AND FUSE BLOCK (J/B) [REAR BLOWER
MOTOR RELAY (COIL SIDE) POWER]
1. Disconnect front air control and fuse block (J/B) connectors
M39.
2. Check continuity between front air control harness connector
M50 terminal 38 (W/L) and fuse block (J/B) connector M39 ter-
minal 3Q (W/L).
OK or NG
OK >> Replace front air control. Refer to ATC-147, "FRONT
AIR CONTROL" .
NG >> Repair harness or connector.Continuity should exist.LJ IA 0 111E

ATC-110
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
COMPONENT INSPECTION
Rear Blower Motor Relay
Check circuit continuity between terminals 3 and 5 by supplying 12
volts and ground to coil side terminals 1 and 2 of relays.
Rear Blower Switch (Rear)
Check continuity between terminals at each switch position.
Rear Blower Switch (Front)
Check continuity between terminals at each switch position.
WJIA2003E
LJ IA0113E
LJ IA0114E

TROUBLE DIAGNOSIS
ATC-111
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: October 20052005 QX56
Rear Blower Motor
Check that there are no foreign particles inside the intake unit.
Apply 12 volts to terminal 2 and ground to terminal 1 and ensure that
the blower motor rotates freely and quietly.
Rear Blower Motor Resistor
Check continuity between terminals. There will be resistance, but
there should not be an open or short between any two terminals.
WJIA1268E
WJIA1269E

ATC-112
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
Rear Air Control CircuitEJS003XU
SYMPTOM:

Temperature cannot be adjusted from the rear air control.
INSPECTION FLOW
*1AT C - 6 0 , "Operational Check
(Rear)"AT C - 6 0 , "Operational Check
(Rear)"
*2AT C - 5 5 , "A/C System Self-diagno-
sis Function"
*3AT C - 5 6 , "SELF-DIAGNOSIS CODE
CHART"
*4AT C - 11 3 , "DIAGNOSTIC PROCE-
DURE FOR REAR AIR CONTROL"
*5AT C - 7 9 , "DIAGNOSTIC PROCE-
DURE FOR AIR MIX DOOR
MOTOR (REAR)"
WJIA1270E

TROUBLE DIAGNOSIS
ATC-113
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: October 20052005 QX56
SYSTEM DESCRIPTION
Component Parts
Rear air control system components are:

Front air control

Rear air control

Air mix door motor (rear)

Rear blower motor relay

Rear blower motor resistor

Rear blower motor
System Operation
Rear Air Control
When the rear blower switch (front) (integral to the front air control) is in the REAR position the rear blower
motor speeds and the rear temperature and mode are controlled by the rear blower switch (rear) and the rear
temperature switch (rear) (both integral to the rear air control).
DIAGNOSTIC PROCEDURE FOR REAR AIR CONTROL
SYMPTOM:

Blower motor operation is malfunctioning. Refer to ATC-101, "Rear Blower Motor Circuit" .

Temperature and mode operation is malfunctioning.
1. CHECK OPERATION FROM FRONT AIR CONTROL
Does rear temperature and mode operate normally from front air control?
YES or NO
YES >> GO TO 2.
NO >> Refer to ATC-79, "
DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR (REAR)" .
WJIA1132E

ATC-114
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
2. CHECK CIRCUIT BETWEEN REAR AIR CONTROL AND FRONT AIR CONTROL FOR OPEN AND
SHORT
1. Turn ignition switch OFF.
2. Disconnect front air control and rear air control connectors.
3. Check continuity between front air control harness connector
M50 terminal 33 (V) and rear air control harness connector
R209 terminal 5 (V).
4. Check continuity between rear air control harness connector
R209 terminal 5 (V) and ground.
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
3. CHECK CIRCUIT BETWEEN REAR AIR CONTROL AND AIR MIX DOOR MOTOR (REAR) FOR OPEN
OR SHORT
1. Disconnect air mix door motor (rear) connector.
2. Check continuity between rear air control harness connector
R209 terminal 2 (P) and 4 (Y) and air mix door motor (rear) har-
ness connector B155 terminal 2 (P) and 3 (Y).
3. Check continuity between rear air control harness connector
R209 terminals 2 (P) and 4 (Y) and ground.
OK or NG
OK >> Replace rear air control.
NG >> Repair harness or connector.33 - 5 Continuity should exist.
5 - Ground Continuity should not exist.
WJIA1441E
2 - 2 Continuity should exist.
4 - 3 Continuity should exist.
2, 4 - Ground Continuity should not exist.
WJIA1442E

TROUBLE DIAGNOSIS
ATC-115
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: October 20052005 QX56
Magnet Clutch CircuitEJS003XV
SYMPTOM: Magnet clutch does not engage.
INSPECTION FLOW
*1ATC-57, "Operational Check (Front)"*2AT C - 5 5 , "A/C System Self-diagnosis
Function"
*3AT C - 5 6 , "SELF-DIAGNOSIS CODE
CHART"
*4ATC-137, "Ambient Sensor Circuit"*5ATC-145, "Intake Sensor Circuit"
WJIA1285E