diagram INFINITI QX4 2005 Factory Service Manual

INJECTOR CIRCUIT
EC-635
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Revision: October 20052005 QX56
3. CHECK INJECTOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect injector harness connector.
3. Turn ignition switch ON.
4. Check voltage between injector terminal 1 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E2, F32

IPDM E/R connector E119

15A fuse

Harness for open or short between injector and fuse
>> Repair harness or connectors.
5. CHECK INJECTOR OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between injector terminal 2 and ECM terminals 21, 22, 23, 40, 41, 42, 44, 63.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 6.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.Voltage: Battery voltage
BBIA0374E
PBIB0582E
Continuity should exist.

EC-638Revision: October 2005
FUEL PUMP CIRCUIT
2005 QX56
Wiring DiagramUBS00HDD
BBWA1714E

FUEL PUMP CIRCUIT
EC-641
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Revision: October 20052005 QX56
6. CHECK 15A FUSE
1. Turn ignition switch OFF.
2. Disconnect 15A fuse.
3. Check 15A fuse.
OK or NG
OK >> GO TO 7.
NG >> Replace fuse.
7. CHECK CONDENSER POWER SUPPLY CIRCUIT-II FOR OPEN AND SHORT
1. Disconnect IPDM E/R harness connector E119.
2. Check harness continuity between IPDM E/R terminal 13 and condenser terminal 1.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 13.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8. CHECK CONDENSER GROUND CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between condenser terminal 2 and ground.
Refer to Wiring Diagram.
2. Also check harness for short to power.
OK or NG
OK >> GO TO 9.
NG >> Repair open circuit or short to power in harness or connectors.
9. CHECK CONDENSER
Refer to EC-642, "
Component Inspection" .
OK or NG
OK >> GO TO 10.
NG >> Replace condenser.
10. CHECK FUEL PUMP POWER SUPPLY AND GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect “fuel level sensor unit and fuel pump” harness con-
nector.
3. Disconnect IPDM E/R harness connector E119.
4. Check harness continuity between IPDM E/R terminal 13 and
“fuel level sensor unit and fuel pump” terminal 1, “fuel level sen-
sor unit and fuel pump” terminal 3 and ground.
Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 12.
NG >> GO TO 11.Continuity should exist.
Continuity should exist.
Continuity should exist.
BBIA0583E

EC-644Revision: October 2005
REFRIGERANT PRESSURE SENSOR
2005 QX56
Wiring DiagramUBS00HDI
BBWA1715E

EC-646Revision: October 2005
REFRIGERANT PRESSURE SENSOR
2005 QX56
3. CHECK REFRIGERANT PRESSURE SENSOR POWER SUPPLY CIRCUIT
1. Disconnect refrigerant pressure sensor harness connector.
2. Turn ignition switch ON.
3. Check voltage between refrigerant pressure sensor terminal 1
and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E5, F14

Harness for open or short between ECM and refrigerant pressure sensor
>> Repair harness or connectors.
5. CHECK REFRIGERANT PRESSURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between refrigerant pressure sensor terminal 3 and ECM terminal 67.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E5, F14

Harness for open or short between ECM and refrigerant pressure sensor
>> Repair open circuit or short to ground or short to power in harness or connectors.
BBIA0445E
Voltage: Approximately 5V
PBIB0188E
Continuity should exist.

REFRIGERANT PRESSURE SENSOR
EC-647
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Revision: October 20052005 QX56
7. CHECK REFRIGERANT PRESSURE SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 70 and refrigerant pressure sensor terminal 2.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 9.
NG >> GO TO 8.
8. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E5, F14

Harness for open or short between ECM and refrigerant pressure sensor
>> Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> Replace refrigerant pressure sensor.
NG >> Repair or replace.
Removal and InstallationUBS00HDK
REFRIGERANT PRESSURE SENSOR
Refer to ATC-185, "Removal and Installation for Refrigerant Pressure Sensor" . Continuity should exist.

EC-650Revision: October 2005
ICC BRAKE SWITCH
2005 QX56
Wiring DiagramUBS00L25
BBWA1786E

ICC BRAKE SWITCH
EC-653
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Revision: October 20052005 QX56
4. CHECK ICC BRAKE HOLD RELAY POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ICC brake hold relay.
3. Turn ignition switch ON.
4. Check voltage between ICC brake hold relay terminal 4 and
ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors M31, E152

Fuse block (J/B) connector M4

10A fuse

Harness for open or short between ICC brake hold relay and battery
>> Repair open circuit or short to ground or short to power in harness or connectors.
6. CHECK ICC BRAKE SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ICC brake switch harness connector.
3. Check harness continuity between ICC brake hold relay terminal
3 and ICC brake switch terminal 1.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
BBIA0471E
Voltage: Battery voltage
MBIB0059E
Continuity should exist.
BBIA0470E

EC-654Revision: October 2005
ICC BRAKE SWITCH
2005 QX56
7. CHECK ICC BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ICC brake switch terminal 2 and ECM terminal 108.
Refer Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8. CHECK ICC BRAKE HOLD RELAY
Refer to EC-656, "
Component Inspection" .
OK >> GO TO 9.
NG >> Replace ICC brake hold relay.
9. CHECK ICC BRAKE SWITCH
Refer to EC-656, "
Component Inspection" .
OK or NG
OK >> GO TO 14.
NG >> Replace ICC brake switch.
10. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect stop lamp switch harness connector.
3. Check voltage between stop lamp switch terminal 3 and ground
with CONSULT -II or tester.
OK or NG
OK >> GO TO 12.
NG >> GO TO 11.Continuity should exist.
BBIA0470E
Voltage: Battery voltage
PBIB2102E

ICC BRAKE SWITCH
EC-655
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Revision: October 20052005 QX56
11 . DETECT MALFUNCTIONING PART
Check the following.

Harness connectors M31, E152

Fuse block (J/B) No. 1 connector M60

10A fuse

Harness for open or short between stop lamp switch and battery
>> Repair open circuit or short to ground or short to power in harness or connectors.
12. CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 101 and stop lamp switch terminal 4.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 13.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
13. CHECK STOP LAMP SWITCH
Refer to EC-656, "
Component Inspection" .
OK or NG
OK >> GO TO 14.
NG >> Replace stop lamp switch.
14. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END Continuity should exist.