2005 INFINITI QX4 relay

ATC-100
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
COMPONENT INSPECTION
Front Blower Motor Relay
Check continuity between terminals by supplying 12 volts and
ground to coil side terminals of relay.
Front Blower Motor
Confirm smooth rotation of the blower motor.

Ensure that there are no foreign particles inside the blower unit.

Apply 12 volts to terminal + and ground to terminal - and verify
that the motor operates freely and quietly.
WJIA1401E
WJIA1265E

ATC-102
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
SYSTEM DESCRIPTION
Component Parts
Rear blower speed control system components are:

Front air control

Rear blower switch (front)

Rear air control

Rear blower motor resistor

Rear blower motor

Rear blower motor relay
System Operation
Rear Blower Control
When the rear blower control dial (front) is in the OFF position, the rear blower motor cannot operate.
When the rear blower control dial (front) is in the REAR position, it allows the rear blower switch (rear) to con-
trol the rear blower motor speed. In any other position (1-4), the rear blower switch (front) controls the rear
blower motor speed regardless of the rear blower switch (rear) position.
DIAGNOSTIC PROCEDURE FOR REAR BLOWER MOTOR
Rear Blower Switch (Rear) Circuit
SYMPTOM:

Rear blower motor does not rotate when rear blower switch (front) is set to REAR position and the rear
blower switch (rear) is set at 1-4 speed.
1. CHECK REAR BLOWER MOTOR OPERATION
Blower motor rotates normally when rear blower control dial (front) is set at 1 - 4 speed.
OK or NG
OK >> GO TO 2.
NG >> Refer to ATC-104, "
Trouble Diagnosis Procedure For Rear Blower Motor (1 - 4 Speed)" .
2. CHECK REAR BLOWER SWITCH (FRONT)
Refer to ATC-110, "
Rear Blower Switch (Front)" .
OK or NG
OK >> GO TO 3.
NG >> Replace rear blower switch (front). Refer to ATC-147, "
FRONT AIR CONTROL" .
WJIA1280E

TROUBLE DIAGNOSIS
ATC-105
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Revision: October 20052005 QX56
1. DIAGNOSTIC PROCEDURE
Blower motor rotates normally at each speed.
OK or NG
OK >> Inspection End.
NG >> 1. Does not rotate at any speed, GO TO 2.
2. Does not rotate at 1 - 3 speed, GO TO 13.
3. Does not rotate at 4 speed, GO TO 18.
2. CHECK FUSES
Check 15A fuses [Nos. 10 and 11, located in the fuse block (J/B)]. Refer to PG-76, "
FUSE BLOCK-JUNCTION
BOX(J/B)" .
OK or NG
OK >> GO TO 3.
NG >> GO TO 8.
3. CHECK REAR BLOWER MOTOR POWER SUPPLY
1. Turn ignition switch OFF.
2. Disconnect rear blower motor connector.
3. Select any rear blower speed except OFF.
4. Turn ignition switch ON.
5. Check voltage between rear blower motor harness connector
B134 terminal 2 (L/R) and ground.
OK or NG
OK >> GO TO 11.
NG >> GO TO 4.
4. CHECK REAR BLOWER MOTOR RELAY
Turn ignition switch OFF.
Refer to AT C - 11 0 , "
Rear Blower Motor Relay" .
OK or NG
OK >> GO TO 5.
NG >> Replace rear blower motor relay.
5. CHECK REAR BLOWER MOTOR POWER FROM RELAY TO REAR BLOWER MOTOR
1. Reconnect rear blower motor connector.
2. Disconnect rear blower motor relay J-1.
3. Turn ignition switch ON.
4. Set rear blower switch (front) to any position except OFF, REAR,
or 4 - speed.
5. Momentarily (no more than 4 seconds), connect a jumper wire
between rear blower motor relay connector J-1 (harness side)
terminals 3 and 5.
OK or NG
OK >> GO TO 6.
NG >> GO TO 10.2 - Ground : Battery voltage.
WJIA0596E
Rear blower motor should rotate.WJIA2002E

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
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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

TROUBLE DIAGNOSIS
ATC-109
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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-113
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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