ignition INFINITI QX56 2004 Factory Service Manual

ATC-82
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
5. CHECK PBR GROUND REFERENCE CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49.
3. Check continuity between defroster door motor harness connec-
tor M144 terminal 2 (P) and front air control harness connector
M49 terminal 15 (P).
OK or NG
OK >> GO TO 6.
NG >> Repair or replace harness as necessary.
6. CHECK PBR FEEDBACK SIGNAL
1. Reconnect front air control connector and defroster door motor
connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M49
terminal 25 (LG/B) and ground.
4. Change mode between floor, defroster, and panel.
OK or NG
OK >> Replace front air control. Refer to ATC-135, "FRONT
AIR CONTROL" .
NG >> GO TO 7.
7. CHECK PBR FEEDBACK CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect defroster door motor connector M144 and front air
control connector M49.
3. Check continuity between defroster door motor harness connec-
tor M144 terminal 4 (LG/B) and front air control harness connec-
tor M49 terminal 25 (LG/B).
OK or NG
OK >> Replace defroster door motor. Refer to ATC-150,
"Removal and Installation" .
NG >> Repair or replace harness as necessary.2 - 15 : Continuity should exist.
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25 - Ground : Approx. 0 - 5V
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4 - 25 : Continuity should exist.
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ATC-86
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
1. CHECK FUSES
Check 20A fuses [No. 24 and 27 (located in the fuse and fusible link box)]. For fuse layout. Refer to PG-77,
"FUSE AND FUSIBLE LINK BOX" .
OK or NG
OK >> GO TO 2.
NG >> GO TO 10.
2. CHECK FRONT BLOWER MOTOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front blower motor connector M62.
3. Turn ignition switch ON.
4. Press the MODE switch to select any mode except OFF.
5. Set front fan switch to high.
6. Check voltage between front blower motor harness connector
M62 terminal 2 (W/L) and ground.
OK or NG
OK >> GO TO 12.
NG >> GO TO 3.
3. CHECK FRONT BLOWER MOTOR RELAY (SWITCH SIDE) POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front blower motor relay M107.
3. Check voltage between front blower motor relay harness con-
nector M107 terminals 5 (GR) and 7 (P), and ground.
OK or NG
OK >> GO TO 4.
NG >> Repair harness or connector.
4. CHECK FRONT BLOWER MOTOR RELAY
Refer to ATC-89, "
Front Blower Motor Relay" .
OK or NG
OK >> GO TO 5.
NG >> Replace front blower motor relay.
5. CHECK FRONT BLOWER MOTOR RELAY (SWITCH SIDE) CIRCUIT FOR OPEN
1. Turn ignition switch OFF.
2. Disconnect blower motor relay connector M107 and front blower
motor connector M62.
3. Check continuity between front blower motor relay harness con-
nector M107 terminals 3 (W/L) and 6 (W/L)
and front blower motor harness connector M62 terminal 2 (W/L).
OK or NG
OK >> GO TO 6.
NG >> Repair harness or connector.2 - Ground : Battery voltage should exist.
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5, 7 - Ground : Battery voltage should exist.
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3, 6 - 2 : Continuity should exist.
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TROUBLE DIAGNOSIS
ATC-87
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6. CHECK VARIABLE BLOWER CONTROL POWER SUPPLY CIRCUIT FOR OPEN
1. Disconnect variable blower control connector M122.
2. Check continuity between front blower motor relay harness con-
nector M107 terminals 3 (W/L) and 6 (W/L), and variable blower
control harness connector M122 terminal 1 (W/L).
OK or NG
OK >> GO TO 7.
NG >> Repair harness or connector.
7. CHECK VARIABLE BLOWER CONTROL SIGNAL CIRCUIT
1. Disconnect front air control connector M49.
2. Check continuity between front air control harness connector
M49 terminal 13 (G/R) and variable blower control harness con-
nector M122 terminal 2 (G/R).
OK or NG
OK >> GO TO 8.
NG >> Repair harness or connector.
8. CHECK FRONT BLOWER MOTOR RELAY (COIL SIDE) POWER SUPPLY
1. Turn ignition switch ON.
2. Check voltage between front blower motor relay harness con-
nector M107 terminal 1 (Y/G) and ground.
OK or NG
OK >> GO TO 9.
NG >> Repair harness or connector.
9. CHECK FRONT BLOWER MOTOR RELAY (COIL SIDE) GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check continuity between front blower motor relay harness con-
nector M107 terminal 2 (R/B) and front air control harness con-
nector M49 terminal 26 (R/B).
OK or NG
OK >> Replace front air control. Refer to ATC-135, "FRONT
AIR CONTROL" .
NG >> Repair harness or connector.3, 6 - 1 : Continuity should exist.
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13 - 2 : Continuity should exist.
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1 - Ground : Battery voltage should exist.
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2 - 26 : Continuity should exist.
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ATC-88
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
10. REPLACE FUSES
1. Replace fuses.
2. Activate the front blower motor.
3. Do fuses blow?
YES or NO
YES >> GO TO 11.
NO >> Inspection End.
11 . CHECK FRONT BLOWER MOTOR POWER SUPPLY CIRCUIT FOR SHORT
1. Turn ignition switch OFF.
2. Disconnect variable blower control connector M122.
3. Check continuity between variable blower control harness con-
nector M122 terminal 1 (W/L) and ground.
OK or NG
OK >> GO TO 12.
NG >> Repair harness or connector.
12. CHECK VARIABLE BLOWER CONTROL SIGNAL CIRCUIT
1. Disconnect front air control connector M49.
2. Check continuity between front air control harness connector
M49 terminal 13 (G/R) and variable blower control harness con-
nector M122 terminal 2 (G/R).
OK or NG
OK >> Check blower motor, if OK replace variable blower con-
trol. Refer to ATC-89, "
Front Blower Motor" .
NG >> Repair harness or connector.1 - Ground. : Continuity should not exist.
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13 - 2 : Continuity should exist.
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ATC-92
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
1. CHECK REAR BLOWER MOTOR OPERATION
Blower motor rotates normally when rear fan switch (front) is set at 1 - 4 speed.
OK or NG
OK >> GO TO 2.
NG >> Refer to AT C - 9 3 , "
Trouble Diagnosis Procedure For Rear Blower Motor (1 - 4 Speed)" .
2. CHECK REAR FAN SWITCH (FRONT)
Refer to ATC-99, "
Rear Fan Switch (Front)" .
OK or NG
OK >> GO TO 3.
NG >> Replace rear fan switch (front). Refer to ATC-135, "
FRONT AIR CONTROL"
3. CHECK REAR FAN SWITCH (REAR)
Refer to ATC-99, "
Rear Fan Switch (Rear)" .
OK or NG
OK >> GO TO 4.
NG >> Replace rear fan switch (rear). Refer to ATC-135, "
REAR AIR CONTROL" .
4. CHECK CIRCUIT CONTINUITY
1. Turn ignition switch OFF.
2. Disconnect rear fan switch (front) connector M52 and rear fan
switch (rear) (Rear air control) connector R208.
3. Check voltage between rear fan switch (front) harness connec-
tor M52 terminal 2 (BR) and rear fan switch (rear) (Rear air con-
trol) harness connector R208 terminal 10 (BR).
OK or NG
OK >> Inspection End.
NG >> Repair harness or connector.2 - 10 : Continuity should exist.WJIA0794E

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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TROUBLE DIAGNOSIS
ATC-103
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Revision: August 20072004 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 M50 and rear temperature/mode dial
(rear) (Rear air control) connector R209.
3. Check continuity between front air control harness connector
M50 terminal 33 (V) and rear temperature/mode dial (rear)
(Rear air control) connector R209 terminal 5 (V).
4. Check continuity between rear temperature/mode dial (rear)
(Rear air control) 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 B155.
2. Check continuity between rear temperature/mode dial (rear)
(Rear air control) connector R209 terminal 2 (P) and 4 (Y) and
air mix door motor (rear) harness connector B155 terminal 2 (P)
and 3 (Y).
3. Check continuity between rear temperature/mode dial (rear)
(Rear air control) connector R209 terminals 2 (P) and 4 (Y) and
ground.
OK or NG
OK >> Replace rear air control [rear temperature/mode dial (rear)]. Refer to ATC-135, "REAR AIR CON-
TROL" .
NG >> Repair harness or connector.33 - 5 Continuity should exist.
5 - Ground Continuity should not exist.
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2 - 2 Continuity should exist.
4 - 3 Continuity should exist.
2, 4 - Ground Continuity should not exist.
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