2004 INFINITI QX56 ignition

ATC-72
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
3. CHECK PBR REFERENCE SIGNAL VOLTAGE
1. Turn ignition switch OFF.
2. Disconnect air mix door motor (Passenger) connector M143.
3. Turn ignition switch ON.
4. Check voltage between air mix door motor (Passenger) harness
connector M143 terminal 3 (Y) and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. CHECK PBR REFERENCE VOLTAGE CIRCUIT BETWEEN AIR MIX DOOR (PASSENGER) AND
FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49.
3. Check continuity between air mix door motor (Passenger) har-
ness connector M143 terminal 3 (Y) and front air control harness
connector M49 terminal 2 (Y).
OK or NG
OK >> Replace front air control. Refer to ATC-135, "FRONT
AIR CONTROL" .
NG >> Repair or replace harness as necessary.
5. CHECK PBR GROUND REFERENCE CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49.
3. Check continuity between air mix door motor (Passenger) har-
ness connector M143 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 air mix door motor
(Passenger) connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M50
terminal 41 (R/W) and ground.
4. Rotate temperature dial (Passenger) through complete range.
OK or NG
OK >> Replace front air control. Refer to ATC-135, "FRONT
AIR CONTROL" .
NG >> GO TO 7. 3 - Ground : Approx.5V
LJIA0044E
3 - 2 Continuity should exist.
LJIA0045E
2 - 15 Continuity should exist.
WJIA0549E
41 - Ground : Approx. 0 - 5V
LJIA0047E

TROUBLE DIAGNOSIS
ATC-73
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: August 20072004 QX56
7. CHECK PBR FEEDBACK CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect air mix door motor (Passenger) connector M143 and
front air control connector M50.
3. Check continuity between air mix door motor (Passenger) har-
ness connector M143 terminal 4 (R/W) and front air control har-
ness connector M50 terminal 41 (R/W).
OK or NG
OK >> Replace air mix door motor (Passenger). Refer to AT C -
154, "FRONT AIR MIX DOOR MOTOR (PASSENGER)"
.
NG >> Repair or replace harness as necessary.
DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR (REAR)
1. CHECK RESULT FROM FRONT AIR CONTROL SELF-DIAGNOSIS
Self-diagnosis code 38 is present. Refer to ATC-53, "
A/C System Self-diagnosis Function" .
YES or NO
YES >> GO TO 2.
NO >> GO TO 3.
2. CHECK POWER SUPPLY CIRCUIT FOR AIR MIX DOOR MOTOR (REAR)
1. Turn ignition switch OFF.
2. Disconnect front air control connector M50 and air mix door
motor (Rear) connector B155.
3. Check continuity between front air control harness connector
M50 terminal 27 (GR/R) and air mix door motor (Rear) harness
connector B155 terminal 1 (GR/R) and between front air control
harness connector M50 terminal 28 (L/Y) and air mix door motor
(Rear) harness connector B155 terminal 6 (L/Y).
OK or NG
OK >> Replace air mix door motor (Rear). Refer to ATC-154, "REAR AIR MIX DOOR MOTOR" .
NG >> Repair or replace harness as necessary.
3. CHECK PBR REFERENCE SIGNAL VOLTAGE
1. Turn ignition switch OFF.
2. Disconnect air mix door motor (Rear) connector B155.
3. Turn ignition switch ON.
4. Check voltage between air mix door motor (Rear) harness con-
nector B155 terminal 3 (Y) and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.4 - 41 : Continuity should exist.
WJIA0550E
27 - 1 Continuity should exist.
28 - 6 Continuity should exist.
LJIA0049E
3 - Ground : Approx. 5V
LJIA0050E

ATC-74
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
4. CHECK PBR REFERENCE VOLTAGE CIRCUIT BETWEEN AIR MIX DOOR MOTOR (REAR) AND
FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49.
3. Check continuity between air mix door motor (Rear) harness
connector B155 terminal 3 (Y) and front air control harness con-
nector M49 terminal 2 (Y).
OK or NG
OK >> Replace front air control. Refer to ATC-135, "FRONT
AIR CONTROL" .
NG >> Repair or replace harness as necessary.
5. CHECK PBR GROUND REFERENCE CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49.
3. Check continuity between air mix door motor (Rear) harness
connector B155 terminal 2 (P) and front air control harness con-
nector 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 air mix door motor
(Rear) connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M50
terminal 42 (R/Y) and ground.
4. Rotate rear temperature/mode dial (Front) through complete
range.
OK or NG
OK >> Replace front air control. Refer to ATC-135, "FRONT
AIR CONTROL" .
NG >> GO TO 7.3 - 2 Continuity should exist.
LJIA0051E
2 - 15 Continuity should exist.
LJIA0052E
42 - Ground : Approx. 0 - 5V
LJIA0053E

TROUBLE DIAGNOSIS
ATC-75
C
D
E
F
G
H
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K
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MA
B
AT C
Revision: August 20072004 QX56
7. CHECK PBR FEEDBACK CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect air mix door motor (Rear) connector B155 and front
air control connector M50.
3. Check continuity between air mix door motor (Rear) harness
connector B155 terminal 4 (R/Y) and front air control harness
connector M50 terminal 42 (R/Y).
OK or NG
OK >> Replace air mix door motor (Rear) ATC-154, "REAR AIR
MIX DOOR MOTOR" .
NG >> Repair or replace harness as necessary.4 - 42 Continuity should exist.LJIA0054E

ATC-78
TROUBLE DIAGNOSIS
Revision: August 20072004 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 RESULT FROM FRONT AIR CONTROL SELF-DIAGNOSIS
Self-diagnosis code 72 is present. Refer to ATC-53, "
A/C System Self-diagnosis Function" .
YES or NO
YES >> GO TO 2.
NO >> Replace front air control. Refer to ATC-135, "
FRONT AIR CONTROL" .
2. CHECK POWER SUPPLY CIRCUIT FOR INTAKE DOOR MOTOR
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49 and intake door
motor connector M58.
3. Check continuity between front air control harness connector
M49 terminal 7 (O) and intake door motor harness connector
M58 terminal 1 (O) and between front air control harness con-
nector M49 terminal 8 (G/B) and intake door motor harness con-
nector M58 terminal 6 (G/B).
OK or NG
OK >> Replace intake door motor. Refer to ATC-151, "INTAKE DOOR MOTOR" .
NG >> Repair or replace harness as necessary.
WJIA0552E
7 - 1 Continuity should exist.
8 - 6 Continuity should exist.
WJIA0591E

TROUBLE DIAGNOSIS
ATC-81
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MA
B
AT C
Revision: August 20072004 QX56
DIAGNOSTIC PROCEDURE FOR DEFROSTER DOOR MOTOR
1. CHECK RESULT FROM FRONT AIR CONTROL SELF-DIAGNOSIS
Self-diagnosis code 62 is present. Refer to ATC-53, "
A/C System Self-diagnosis Function" .
YES or NO
YES >> GO TO 2.
NO >> GO TO 3.
2. CHECK POWER SUPPLY CIRCUIT FOR DEFROSTER DOOR MOTOR
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49 and defroster door
motor connector M144.
3. Check continuity between front air control harness connector
M49 terminal 19 (LG) and defroster door motor harness connec-
tor M144 terminal 1 (LG) and between front air control harness
connector M49 terminal 20 (P/B) and defroster door motor con-
nector M144 terminal 6 (P/B).
OK or NG
OK >> Replace defroster door motor. Refer to ATC-150, "Removal and Installation" .
NG >> Repair or replace harness as necessary.
3. CHECK PBR REFERENCE SIGNAL VOLTAGE
1. Disconnect defroster door motor harness connector M144.
2. Turn ignition switch ON.
3. Check voltage between defroster door motor harness connector
M144 terminal 3 (Y) and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. CHECK PBR REFERENCE VOLTAGE CIRCUIT BETWEEN DEFROSTER DOOR MOTOR AND FRONT
AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49.
3. Check continuity between defroster door motor harness connec-
tor M144 terminal 3 (Y) and front air control harness connector
M49 terminal 2 (Y).
OK or NG
OK >> Replace front air control. Refer to ATC-135, "FRONT
AIR CONTROL" .
NG >> Repair or replace harness as necessary.19 - 1 : Continuity should exist.
20 - 6 : Continuity should exist.
WJIA0553E
3 - Ground : Approx. 5V
WJIA0554E
3 - 2 : Continuity should exist.
WJIA0555E

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.
WJIA0556E
25 - Ground : Approx. 0 - 5V
WJIA0770E
4 - 25 : Continuity should exist.
WJIA0558E

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.
WJIA1331E
5, 7 - Ground : Battery voltage should exist.
WJIA0780E
3, 6 - 2 : Continuity should exist.
WJIA0781E