ignition INFINITI QX56 2004 Factory Service Manual

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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ATC-107
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6. CHECK CIRCUIT CONTINUITY BETWEEN BCM AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect BCM connector M18 and front air control connector
M49.
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-135,
"FRONT AIR CONTROL" .
NG-2 >> If the voltage is approx. 0V when A/C switch is OFF, replace BCM. Refer to BCS-19, "
Removal
and Installation of BCM" . 27 - 12 Continuity should exist.
WJIA0809E
Te r m i n a l s
ConditionVoltag e
(Approx.) (+)
(-) Front air
control con-
nectorTe r m i n a l N o .
(Wire color)
M49 12 (W/R) GroundA/C switch: ON 0V
A/C switch: OFF 5V
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ATC-108
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
8. CHECK REFRIGERANT PRESSURE SENSOR
WITH CONSULT-II
1. Start engine.
2. Check voltage of refrigerant pressure sensor. Refer to AT C - 3 3 , "
CONSULT-II Function (BCM)" .
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-607, "
REFRIGERANT PRESSURE SENSOR" .
9. CHECK BCM INPUT (FAN ON) SIGNAL
Check FAN ON/OFF signal while changing the front switch position.
Refer to ATC-33, "
CONSULT-II Function (BCM)" .
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 M18 and front air control connector
M49.
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 FAN SWITCH ON : FAN ON SIG ON
FRONT FAN SWITCH OFF : FAN ON SIG OFF
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28 - 10 Continuity should exist.
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ATC-109
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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 >> Check CAN communication. Refer to ATC-32, "CAN Communication System Description" .
NG-1 >> If the voltage is approx. 5V when blower motor is ON, replace front air control. Refer to ATC-135,
"FRONT AIR CONTROL" .
NG-2 >> If the voltage is approx. 0V when blower motor is OFF, replace BCM. Refer to BCS-19, "
Removal
and Installation of BCM" .
Te r m i n a l s
ConditionVo ltag e
(Approx.) (+)
(-)
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
operates0V
A/C switch: OFF 5V
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ATC-122
TROUBLE DIAGNOSIS
Revision: August 20072004 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. Turn ignition switch ON.
4. 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-135, "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/G)
GroundBattery voltage Battery voltage
3 (G/Y) 0V Battery voltage
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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
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1 - 29 : Continuity should exist.
1 - Ground : Continuity should not exist.
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ATC-123
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4. CHECK WATER VALVE RELAY
Check water valve relay. Refer to ATC-124, "
Wat er Va lve Relay" .
OK or NG
OK >> GO TO 5.
NG >> Replace water valve relay.
5. CHECK WATER VALVE GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect water valve connector E141.
3. Check continuity between water valve harness connector E141
terminal - (B) and ground.
OK or NG
OK >> GO TO 6.
NG >> Repair harness or connector.
6. CHECK WATER VALVE POWER CIRCUIT
1. Check continuity between water valve relay connector terminal 5
(Y/L) and water valve connector E141 terminal + (Y/L)
2. Check continuity between water valve relay harness connector
M7 terminal 5 (Y/L) and ground.
OK or NG
OK >> Replace water valve.
NG >> Repair harness or connector.(-) - Ground : Continuity should exist.
WJIA0816E
5 - + : Continuity should exist.
5 - Ground : Continuity should not exist.
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TROUBLE DIAGNOSIS
ATC-125
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Revision: August 20072004 QX56
Ambient Sensor CircuitEJS002CS
COMPONENT DESCRIPTION
Ambient Sensor
The ambient sensor is attached on the radiator core support (left
side). It detects ambient temperature and converts it into a value
which is then input into the front air control.
AMBIENT TEMPERATURE INPUT PROCESS
The front air control includes a processing circuit for the ambient sensor input. However, when the tempera-
ture detected by the ambient sensor increases quickly, the processing circuit retards the front air control func-
tion. It only allows the front air control to recognize an ambient temperature increase of 0.33°C (0.6°F) per 100
seconds.
This prevents constant adjustments due to momentary conditions, such as stopping after high speed driving.
Although the actual ambient temperature has not changed, the temperature detected by the ambient sensor
will increase. This is because the heat from the engine compartment can radiate to the front grille area, loca-
tion of the ambient sensor.
DIAGNOSTIC PROCEDURE FOR AMBIENT SENSOR
SYMPTOM: Ambient sensor circuit is open or shorted. (40 or 41 is
indicated as a result of conducting the front air control self-diagnosis)
1. CHECK VOLTAGE BETWEEN AMBIENT SENSOR AND GROUND
1. Disconnect ambient sensor connector E1.
2. Turn ignition switch ON.
3. Check voltage between ambient sensor harness connector E1
terminal 1 (P) and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
WJIA0819E
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1 - Ground : Approx. 5V
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ATC-126
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
2. CHECK CIRCUIT CONTINUITY BETWEEN AMBIENT SENSOR AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49.
3. Check continuity between ambient sensor harness connector
E1 terminal 2 (V/R) and front air control harness connector M49
terminal 21 (V/R).
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
3. CHECK AMBIENT SENSOR
Refer to ATC-127, "
Ambient Sensor" .
OK or NG
OK >> 1. Replace front air control. Refer to ATC-135, "FRONT AIR CONTROL" .
2. Go to self-diagnosis ATC-53, "
A/C System Self-diagnosis Function" and perform self-diagno-
sis.
NG >> 1. Replace ambient sensor. Refer to ATC-136, "
AMBIENT SENSOR" .
2. Go to self-diagnosis ATC-53, "
A/C System Self-diagnosis Function" and perform self-diagno-
sis.
4. CHECK CIRCUIT CONTINUITY BETWEEN AMBIENT SENSOR AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49.
3. Check continuity between ambient sensor harness connector
E1 terminal 1 (P) and front air control harness connector M49
terminal 17 (P).
4. Check continuity between ambient sensor harness connector
E1 terminal 2 (V/R) and ground.
OK or NG
OK >> 1. Replace front air control. Refer to ATC-135, "FRONT AIR CONTROL" .
2. Go to self-diagnosis ATC-53, "
A/C System Self-diagnosis Function" and perform self-diagno-
sis.
NG >> Repair harness or connector.2 - 21 : Continuity should exist.
WJIA0820E
1 - 17 : Continuity should exist.
1 - Ground : Continuity should not exist.
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TROUBLE DIAGNOSIS
ATC-129
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Revision: August 20072004 QX56
DIAGNOSTIC PROCEDURE FOR IN-VEHICLE SENSOR
SYMPTOM: In-vehicle sensor circuit is open or shorted. (30 or 31 is
indicated as a result of conducting self-diagnosis.
1. CHECK IN-VEHICLE SENSOR CIRCUIT
Are diagnostic codes 44 or 46 present?
YES or NO
YES >> GO TO 6.
NO >> GO TO 2.
2. CHECK VOLTAGE BETWEEN IN-VEHICLE SENSOR AND GROUND
1. Disconnect in-vehicle sensor connector M32.
2. Turn ignition switch ON.
3. Check voltage between in-vehicle sensor harness connector
M32 terminal 4 (LG/R) and ground.
OK or NG
OK >> GO TO 3.
NG >> GO TO 5.
3. CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49.
3. Check continuity between in-vehicle sensor harness connector
M32 terminal 1 (V/R) and front air control harness connector
M49 terminal 21 (V/R).
OK or NG
OK >> GO TO 4.
NG >> Repair harness or connector.
4. CHECK IN-VEHICLE SENSOR
Refer to ATC-131, "
In-vehicle Sensor" .
OK or NG
OK >> 1. Replace front air control. Refer to ATC-135, "FRONT AIR CONTROL" .
2. Go to AT C - 5 3 , "
A/C System Self-diagnosis Function" and perform self-diagnosis.
NG >> 1. Replace in-vehicle sensor. Refer to ATC-137, "
IN-VEHICLE SENSOR" .
2. Go to AT C - 5 3 , "
A/C System Self-diagnosis Function" and perform self-diagnosis.
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4 - Ground : Approx. 5V
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1 - 21 : Continuity should exist.
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ATC-130
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
5. CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector M50.
3. Check continuity between in-vehicle sensor harness connector
M32 terminal 4 (LG/R) and front air control harness connector
M50 terminal 32 (LG/R).
4. Check continuity between in-vehicle sensor harness connector
M32 terminal 4 (LG/R) and ground.
OK or NG
OK >> 1. Replace front air control. Refer to ATC-135, "FRONT AIR CONTROL" .
2. Go to self-diagnosis ATC-53, "
A/C System Self-diagnosis Function" and perform self-diagno-
sis.
NG >> Repair harness or connector.
6. CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR MOTOR AND FRONT AIR CON-
TROL (SELF-DIAGNOSIS CODES 44 OR 46)
1. Turn ignition switch OFF.
2. Disconnect front air control connector M50 and in-vehicle sensor
connector M32.
3. Check continuity between in-vehicle sensor harness connector
M32 terminal 2 (O/B) and 3 (BR/Y) and front air control harness
connector M50 terminal 44 (O/B) and 43 (BR/Y).
4. Check continuity between in-vehicle sensor harness connector
M32 terminal 2 (O/B) and 3 (BR/Y) and ground.
OK or NG
OK >> 1. Replace front air control. Refer to ATC-135, "FRONT AIR CONTROL" .
2. Go to ATC-53, "
A/C System Self-diagnosis Function" and perform self-diagnosis.
NG >> Repair harness or connector.4 - 32 : Continuity should exist.
4 - Ground Continuity should not exist.
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2 - 44 : Continuity should exist.
3 - 43 : Continuity should exist.
2, 3 - Ground :Continuity should not exist.
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