2005 INFINITI QX4 ignition

TROUBLE DIAGNOSIS
ATC-107
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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
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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

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-117
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AT C
Revision: October 20052005 QX56
2. PERFORM AUTO ACTIVE TEST
Refer to PG-22, "
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 and compressor (magnet
clutch) connector.
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-28, "Removal and
Installation of IPDM E/R" .
NG >> Replace magnet clutch. Refer to ATC-180, "
Removal
and Installation for Compressor Clutch" .
5. CHECK BCM INPUT (COMPRESSOR ON) SIGNAL
Check compressor ON/OFF signal. Refer to ATC-33, "
CONSULT-II
Function (HVAC)" .
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
WJIA0469E

ATC-118
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
6. CHECK CIRCUIT CONTINUITY BETWEEN BCM AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect BCM connector and front air control connector.
3. Check continuity between BCM harness connector M18 terminal
27 (W/R) and front air control harness connector M49 terminal
12 (W/R).
OK or NG
OK >> GO TO 7.
NG >> Repair harness or connector.
7. CHECK VOLTAGE FOR FRONT AIR CONTROL (COMPRESSOR ON SIGNAL)
1. Reconnect BCM connector and front air control connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M49
terminal 12 (W/R) and ground.
OK or NG
OK >> GO TO 8.
NG-1 >> If the voltage is approx. 5V when A/C switch is ON, replace front air control. Refer to ATC-147,
"FRONT AIR CONTROL" .
NG-2 >> If the voltage is approx. 0V when A/C switch is OFF, replace BCM. Refer to BCS-20, "
Removal
and Installation of BCM" . 27 - 12 Continuity should exist.
WJIA1443E
Terminals
Condition Voltage (+)
(-) Front air
control con-
nectorTe r m i n a l N o .
(Wire color)
M49 12 (W/R) GroundA/C switch: ON Approx. 0V
A/C switch: OFF Approx. 5V
WJIA0449E

TROUBLE DIAGNOSIS
ATC-119
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Revision: October 20052005 QX56
8. CHECK REFRIGERANT PRESSURE SENSOR
WITH CONSULT-II
1. Start engine.
2. Check voltage of refrigerant pressure sensor. Refer to ATC-33, "
CONSULT-II Function (HVAC)" .
WITHOUT CONSULT-II
1. Start engine.
2. Check voltage between ECM harness connector F54 terminal
70 (B/W) and ground.
OK or NG
OK >>
WITH CONSULT-II
GO TO 9.

WITHOUT CONSULT-II
GO TO 10.
NG >> Refer to EC-643, "
REFRIGERANT PRESSURE SENSOR" .
9. CHECK BCM INPUT (FAN ON) SIGNAL
Check FAN ON/OFF signal. Refer to ATC-33, "
CONSULT-II Function
(HVAC)" .
OK or NG
OK >> GO TO 12.
NG >> GO TO 10.
10. CHECK CIRCUIT CONTINUITY BETWEEN BCM AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect BCM connector and front air control connector.
3. Check continuity between BCM harness connector M18 terminal
28 (L/R) and front air control harness connector M49 terminal 10
(L/R).
OK or NG
OK >> GO TO 11.
NG >> Repair harness or connector.
Te r m i n a l s
Condition Voltage (+)
(-)
ECM con-
nectorTe r m i n a l N o .
(Wire color)
F54 70 (B/W) Ground A/C switch: ON Approx. 0.36 - 3.88V
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FRONT BLOWER CONTROL
DIAL ON: FAN ON SIG ON
FRONT BLOWER CONTROL
DIAL OFF: FAN ON SIG OFF
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28 - 10 Continuity should exist.
WJIA0450E

ATC-120
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
11 . CHECK VOLTAGE FOR FRONT AIR CONTROL (FAN ON SIGNAL)
1. Reconnect BCM connector and front air control connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M49
terminal 10 (L/R) and ground.
OK or NG
OK >> GO TO 12.
NG-1 >> If the voltage is approx. 5V when blower motor is ON, replace front air control. Refer to ATC-147,
"FRONT AIR CONTROL" .
NG-2 >> If the voltage is approx. 0V when blower motor is OFF, replace BCM. Refer to BCS-20, "
Removal
and Installation of BCM" .
12. CHECK CAN COMMUNICATION
Check CAN communication. Refer to LAN-5, "
CAN COMMUNICATION" .

BCM – ECM

ECM – IPDM E/R

ECM – Front air control
OK or NG
OK >> Inspection End.
NG >> Repair or replace malfunctioning part(s).
Terminals
Condition Voltage (+)
(-)
Front air con-
trol connectorTe r m i n a l N o .
(Wire color)
M49 10 (L/R) GroundA/C switch: ON
Blower motor
operatesApprox. 0V
A/C switch: OFF Approx. 5V
WJIA0451E

ATC-134
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
DIAGNOSTIC PROCEDURE FOR WATER VALVE
1. CHECK WATER VALVE RELAY POWER INPUT CIRCUITS
1. Turn ignition switch OFF.
2. Disconnect water valve relay connector M7.
3. Check voltage between water valve relay harness connector ter-
minals and ground.
OK or NG
OK >> GO TO 2.
NG >> Repair harness or connector.
2. CHECK WATER VALVE CONTROL
1. Turn ignition switch ON.
2. Select MAX A/C with mode switch.
3. Check continuity between water valve relay harness connector
M7 terminal 1 (W/G) and ground, as MAX A/C is switched OFF
and ON.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. CHECK WATER VALVE CONTROL OUTPUT CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front air control connector M50.
3. Check continuity between water valve relay harness connector
M7 terminal 1 (W/G) and front air control harness connector
M50 terminal 29 (W/G).
4. Check continuity between water valve relay harness connector
M7 terminal 1 (W/G) and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-147, "FRONT AIR CONTROL" .
NG >> Repair harness or connector.
Terminals Ignition switch position
(+)
(-) OFF ON Water valve
relay con-
nectorTe r m i n a l N o .
(Wire color)
M72 (Y/R)
GroundBattery voltage Battery voltage
3 (Y/G) 0V Battery voltage
WJIA0900E
Terminals
Condition Continuity (+)
(-) Water valve
relay con-
nectorTe r m i n a l N o .
(Wire color)
M7 1 (W/G) GroundMAX A/C: ON Yes
MAX A/C: OFF No
WJIA0901E
1 - 29 : Continuity should exist.
1 - Ground : Continuity should not exist.
WJIA0902E