Ins INFINITI QX56 2004 Factory Service Manual

ATC-94
TROUBLE DIAGNOSIS
Revision: August 20072004 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 B134.
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
Refer to ATC-99, "
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. Turn ignition switch OFF.
2. Reconnect rear blower motor connector.
3. Disconnect rear blower motor relay J1.
4. Turn ignition switch ON.
5. Set rear fan switch (front) to any position except off (0), rear (R),
or 4 - speed.
6. Momentarily (no more than 4 seconds), connect a jumper wire
between rear blower motor relay connector J1 terminals 3 and 5.
OK or NG
OK >> GO TO 6.
NG >> GO TO 10.1 - Ground : Battery voltage should exist.
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Rear blower motor should rotate.LJIA0100E

TROUBLE DIAGNOSIS
ATC-95
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Revision: August 20072004 QX56
6. CHECK REAR BLOWER MOTOR RELAY (COIL SIDE) POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect fuse block (J/B) connector M39.
3. Turn ignition switch ON.
4. Set rear fan switch (front) to any position except off (0), rear (R),
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. Disconnect fuse block (J/B) connector M3.
3. 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
B134.
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, "Rear
Blower Motor" .
NG >> Repair harness or connector.1 - Ground : Battery voltage should exist.
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7N - Ground : Continuity should exist.
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2 - Ground : Continuity should not exist.
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ATC-96
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
10. CHECK REAR BLOWER MOTOR RELAY (SWITCH SIDE) POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect fuse block (J/B) connector M3 and rear blower motor
connector B134.
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, "
Rear Blower Motor" .
OK or NG
OK >> GO TO 12.
NG >> Replace rear blower motor. Refer to ATC-141, "
REAR BLOWER MOTOR" .
12. CHECK REAR FAN SWITCH (FRONT)
Refer to ATC-99, "
Rear Fan Switch (Front)" .
OK or NG
OK >> GO TO 15.
NG >> Replace rear fan switch (front). Refer to ATC-135, "
FRONT AIR CONTROL" .
13. CHECK REAR BLOWER MOTOR RESISTOR
Refer to ATC-100, "
Rear Blower Motor Resistor" .
OK or NG
OK >> GO TO 14.
NG >> Replace rear blower motor resistor. Refer to ATC-156, "
Removal and Installation" .
14. CHECK REAR FAN SWITCH (FRONT) CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect rear fan switch (front) M52.
3. Reconnect rear blower motor resistor harness connector B133.
4. Turn ignition switch ON.
5. Check voltage between each rear fan switch (front) connector
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.
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Te r m i n a l N o .
Voltage
(Approx.)
(+) (-)
3
Ground 12V 7
8
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TROUBLE DIAGNOSIS
ATC-97
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Revision: August 20072004 QX56
15. CHECK REAR BLOWER MOTOR GROUND CIRCUIT TO REAR BLOWER MOTOR RESISTOR
1. Turn ignition switch OFF.
2. Disconnect rear blower motor connector B134 and rear blower
motor resistor connector B133.
3. Check continuity between rear blower motor connector B134
terminal 1 (L/B) and rear blower motor resistor harness connec-
tor B133 terminal 3 (L/B).
4. Check continuity between rear blower motor connector B134
terminal 1 (L/B) and ground.
OK or NG
OK >> GO TO 16.
NG >> Repair harness or connector.
16. CHECK REAR FAN SWITCH (FRONT) CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect rear fan switch (front) connector M52.
3. Check continuity between rear fan switch (front) connector M52
terminals 3 (LG), 7 (W/L), and 8 (G), and rear blower motor
resistor connector B133 terminals 1 (LG), 4 (W/L), and 2 (G).
OK or NG
OK >> Inspection End.
NG >> Repair harness or connector.
17. CHECK REAR FAN SWITCH (FRONT) CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect rear fan switch (rear) (Rear air control) connector
R208.
3. Check continuity between rear fan switch (front) connector M52
terminals 3 (LG), 5 (L/B), 7 (W/L), and 8 (G), and rear fan switch
(rear) (Rear air control) 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.
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Te r m i n a l N o .
Continuity
Rear fan switch (front) Rear blower motor resistor
31
Should exist 74
82
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Terminal No.
Continuity
Rear fan switch (front) Rear fan switch (rear)
39
Should exist 56
78
87
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ATC-98
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
18. CHECK REAR FAN SWITCH (FRONT)
Refer to ATC-99, "
Rear Fan Switch (Front)" .
OK or NG
OK >> GO TO 19.
NG >> Replace rear fan switch (front). Refer to ATC-135, "
FRONT AIR CONTROL" .
19. CHECK REAR FAN SWITCH (REAR)
Refer to ATC-99, "
Rear Fan Switch (Rear)" .
OK or NG
OK >> Inspection End.
NG >> Replace rear fan switch (rear). Refer to ATC-135, "
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 connector M50 and fuse block (J/B)
connector 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-135, "FRONT
AIR CONTROL"
NG >> Repair harness or connector.38 - 3Q : Continuity should exist.LJ IA 0 111E

TROUBLE DIAGNOSIS
ATC-99
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Revision: August 20072004 QX56
COMPONENT INSPECTION
Rear Blower Motor Relay
Check circuit continuity between terminals by supplying 12 volts and
ground to coil side terminals of relays.
Rear Fan Switch (Rear)
Check continuity between terminals at each switch position.
Rear Fan Switch (Front)
Check continuity between terminals at each switch position.
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ATC-100
TROUBLE DIAGNOSIS
Revision: August 20072004 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.
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TROUBLE DIAGNOSIS
ATC-101
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Revision: August 20072004 QX56
Rear Air Control CircuitEJS002CK
SYMPTOM:

Temperature cannot be adjusted from the rear air control.
INSPECTION FLOW
*1ATC-59, "Operational Check (Rear)"*2AT C - 5 3 , "A/C System Self-diagno-
sis Function"
*3AT C - 5 5 , "SELF-DIAGNOSIS CODE
CHART"
*4ATC-102, "DIAGNOSTIC PROCE-
DURE FOR REAR AIR CONTROL"
*5AT C - 7 3 , "DIAGNOSTIC PROCE-
DURE FOR AIR MIX DOOR
MOTOR (REAR)"
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ATC-104
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
Magnet Clutch CircuitEJS002CL
SYMPTOM: Magnet clutch does not engage.
INSPECTION FLOW
*1AT C - 5 6 , "Operational Check (Front)"*2ATC-53, "A/C System Self-diagnosis
Function"
*3AT C - 5 5 , "SELF-DIAGNOSIS CODE
CHART"
*4ATC-125, "Ambient Sensor Circuit"*5ATC-133, "Intake Sensor Circuit"*6AT C - 3 5 , "SYMPTOM TABLE"
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ATC-106
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
2. PERFORM AUTO ACTIVE TEST
Refer to PG-23, "
Auto Active Test" .
Does magnet clutch operate?
YES or NO
YES >>
WITH CONSULT-II
GO TO 5.

WITHOUT CONSULT-II
GO TO 6.
NO >> Check 10A fuse (No. 42, located in IPDM E/R), and GO TO 3.
3. CHECK CIRCUIT CONTINUITY BETWEEN IPDM E/R AND COMPRESSOR
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R connector E119 and compressor (magnet
clutch) connector F3.
3. Check continuity between IPDM E/R harness connector E119
terminal 11 (Y/B) and compressor harness connector F3 termi-
nal 1 (Y/B).
OK or NG
OK >> GO TO 4.
NG >> Repair harness or connector.
4. CHECK MAGNET CLUTCH CIRCUIT
Check for operation sound when applying battery voltage direct cur-
rent to terminal.
OK or NG
OK >> Replace IPDM E/R. Refer to PG-29, "Removal and
Installation of IPDM E/R" .
NG >> Replace magnet clutch. Refer to ATC-167, "
Removal
and Installation for Compressor Clutch" .
5. CHECK BCM INPUT (COMPRESSOR ON) SIGNAL
Check compressor ON/OFF signal. Refer to AT C - 3 3 , "
CONSULT-II
Function (BCM)" .
OK or NG
OK >> GO TO 8.
NG >> GO TO 6.
11 – 1 : Continuity should exist.
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A/C SW ON : COMP ON SIG ON
A/C SW OFF : COMP ON SIG OFF
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