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![INFINITI QX56 2008 Factory Service Manual ASCD BRAKE SWITCHEC-391
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OK or NG
OK >>
INSPECTION END
NG >> GO TO 7.
3.CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition sw INFINITI QX56 2008 Factory Service Manual ASCD BRAKE SWITCHEC-391
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OK or NG
OK >>
INSPECTION END
NG >> GO TO 7.
3.CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition sw](/manual-img/42/57030/w960_57030-1689.png)
ASCD BRAKE SWITCHEC-391
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OK or NG
OK >>
INSPECTION END
NG >> GO TO 7.
3.CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ASCD brake switch harness connector.
3. Turn ignition switch ON.
4. Check voltage between ASCD brake switch terminal 1 and ground with CONSULT-IIl or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors M31, E152
• Fuse block (J/B) connector M4
• 10A fuse
• Harness for open or short between ASCD brake switch and fuse
>> Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK ASCD BRAKE SWITCH INPUT SIGN AL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 108 and ASCD brake switch terminal 2. Refer to Wiring Diagram.
CONDITION VOLTAGE
Brake pedal: Fully released Approximately 0V
Brake pedal: Slightly depressed Battery voltage
PBIB1537E
BBIA0373E
Voltage: Battery voltage
PBIB0857E
Continuity should exist.
Revision: March 2010 2008 QX56
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![INFINITI QX56 2008 Factory Service Manual EC-392
< COMPONENT DIAGNOSIS >[VK56DE]
ASCD BRAKE SWITCH
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 INFINITI QX56 2008 Factory Service Manual EC-392
< COMPONENT DIAGNOSIS >[VK56DE]
ASCD BRAKE SWITCH
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](/manual-img/42/57030/w960_57030-1690.png)
EC-392
< COMPONENT DIAGNOSIS >[VK56DE]
ASCD BRAKE SWITCH
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.
6.CHECK ASCD BRAKE SWITCH
Refer to EC-393, "
Component Inspection".
OK or NG
OK >> GO TO 11.
NG >> Replace ASCD brake switch.
7.CHECK STOP LAMP SWIT CH 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 -IIl or tester.
OK or NG
OK >> GO TO 9.
NG >> GO TO 8.
8.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors M31, E152
• Fuse block (J/B) 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.
9.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 10.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
BBIA0373E
Voltage: Battery voltage
PBIB2102E
Continuity should exist.
Revision: March 2010 2008 QX56
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![INFINITI QX56 2008 Factory Service Manual COOLING FANEC-395
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COOLING FAN
Diagnosis ProcedureINFOID:0000000001351874
1.CHECK POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. D INFINITI QX56 2008 Factory Service Manual COOLING FANEC-395
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COOLING FAN
Diagnosis ProcedureINFOID:0000000001351874
1.CHECK POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. D](/manual-img/42/57030/w960_57030-1693.png)
COOLING FANEC-395
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COOLING FAN
Diagnosis ProcedureINFOID:0000000001351874
1.CHECK POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R harness connector E120.
3. Check voltage between IPDM E/R terminal 22 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
• 40A fusible link (located in the fuse and fusible link box)
• 25A fusible link (located in the IPDM E/R box) (late production)
• Harness for open or short between IPDM E/R and battery
>> Repair open circuit or short to ground or short to power in harness or connectors.
3.CHECK COOLING FAN MOTOR CIRCUIT FOR OPEN OR SHORT
1. Disconnect cooling fan motor harness connector (1).
2. Check harness continuity between cooling fan motor terminal 1 and IPDM E/R terminal 24, cooling fan motor terminal 2 and
ground.
Refer to wiring diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK COOLING FAN MOTOR
Refer to EC-395, "
Component Inspection".
OK or NG
OK >> GO TO 5.
NG >> Replace cooling fan motor.
5.CHECK INTERMITTENT INCIDENT
Perform GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
OK or NG
OK >> Replace IPDM E/R. Refer to PCS-34, "Removal and Installation of IPDM E/R".
NG >> Repair or replace harness connectors.
Component InspectionINFOID:0000000001351875
COOLING FAN MOTOR
1. Disconnect cooling fan motor harness connector. Voltage: Battery voltage
PBIB2067E
Continuity should exist.
BBIA0742E
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![INFINITI QX56 2008 Factory Service Manual EC-400
< COMPONENT DIAGNOSIS >[VK56DE]
FUEL INJECTOR
2. Disconnect fuel injector harness connector.
3. Turn ignition switch ON.
4. Check voltage between fuel injector terminal 1 and ground with
CONSUL INFINITI QX56 2008 Factory Service Manual EC-400
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FUEL INJECTOR
2. Disconnect fuel injector harness connector.
3. Turn ignition switch ON.
4. Check voltage between fuel injector terminal 1 and ground with
CONSUL](/manual-img/42/57030/w960_57030-1698.png)
EC-400
< COMPONENT DIAGNOSIS >[VK56DE]
FUEL INJECTOR
2. Disconnect fuel injector harness connector.
3. Turn ignition switch ON.
4. Check voltage between fuel injector terminal 1 and ground with
CONSULT-IIl 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 fuel injector and fuse
>> Repair harness or connectors.
5.CHECK FUEL INJECTOR OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between fuel 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.
6.CHECK FUEL INJECTOR
Refer to EC-401, "
Component Inspection".
OK or NG
OK >> GO TO 7.
NG >> Replace malfunctioning fuel injector.
7.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Voltage: Battery voltage
BBIA0374E
PBIB0582E
Continuity should exist.
Revision: March 2010
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![INFINITI QX56 2008 Factory Service Manual EC-404
< COMPONENT DIAGNOSIS >[VK56DE]
FUEL PUMP
2. Disconnect 15A fuse.
3. Check 15A fuse.
OK or NG
OK >> GO TO 7.
NG >> Replace fuse.
7.CHECK CONDENSER-2 POWER SUPPLY
CIRCUIT-II FOR OPEN AND SHORT
INFINITI QX56 2008 Factory Service Manual EC-404
< COMPONENT DIAGNOSIS >[VK56DE]
FUEL PUMP
2. Disconnect 15A fuse.
3. Check 15A fuse.
OK or NG
OK >> GO TO 7.
NG >> Replace fuse.
7.CHECK CONDENSER-2 POWER SUPPLY
CIRCUIT-II FOR OPEN AND SHORT](/manual-img/42/57030/w960_57030-1702.png)
EC-404
< COMPONENT DIAGNOSIS >[VK56DE]
FUEL PUMP
2. Disconnect 15A fuse.
3. Check 15A fuse.
OK or NG
OK >> GO TO 7.
NG >> Replace fuse.
7.CHECK CONDENSER-2 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-2 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-2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between condenser-2
+ 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-2
Refer to EC-405, "
Component Inspection".
OK or NG
OK >> GO TO 10.
NG >> Replace condenser-2.
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.
11 .DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors E41, C1
• Harness for open or short between fuel pump and IPDM E/R
• Harness for open or short between fuel pump and ground Continuity should exist.
Continuity should exist.
Continuity should exist.
BBIA0583E
Revision: March 2010
2008 QX56
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![INFINITI QX56 2008 Factory Service Manual EC-408
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ICC BRAKE SWITCH
1. Turn ignition switch OFF.
2. Disconnect ICC brake switch harness connector.
3. Check harness continuity between ICC brake hold relay terminal INFINITI QX56 2008 Factory Service Manual EC-408
< COMPONENT DIAGNOSIS >[VK56DE]
ICC BRAKE SWITCH
1. Turn ignition switch OFF.
2. Disconnect ICC brake switch harness connector.
3. Check harness continuity between ICC brake hold relay terminal](/manual-img/42/57030/w960_57030-1706.png)
EC-408
< COMPONENT DIAGNOSIS >[VK56DE]
ICC BRAKE SWITCH
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.
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-409, "
Component Inspection".
OK >> GO TO 9.
NG >> Replace ICC brake hold relay.
9.CHECK ICC BRAKE SWITCH
Refer to EC-409, "
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. Continuity should exist.
BBIA0470E
Continuity should exist.
BBIA0470E
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2008 QX56
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![INFINITI QX56 2008 Factory Service Manual ICC BRAKE SWITCHEC-409
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3. Check voltage between stop lamp switch terminal 3 and ground
with CONSULT -IIl or tester.
OK or NG
OK >> GO T INFINITI QX56 2008 Factory Service Manual ICC BRAKE SWITCHEC-409
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3. Check voltage between stop lamp switch terminal 3 and ground
with CONSULT -IIl or tester.
OK or NG
OK >> GO T](/manual-img/42/57030/w960_57030-1707.png)
ICC BRAKE SWITCHEC-409
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3. Check voltage between stop lamp switch terminal 3 and ground
with CONSULT -IIl or tester.
OK or NG
OK >> GO TO 12.
NG >> GO TO 11.
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 SI GNAL 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-409, "
Component Inspection".
OK or NG
OK >> GO TO 14.
NG >> Replace stop lamp switch.
14.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000001365891
ICC BRAKE SWITCH
1. Turn ignition switch OFF.
2. Disconnect ICC brake switch harness connector. Voltage: Battery voltage
PBIB2102E
Continuity should exist.
Revision: March 2010
2008 QX56
Page 1711 of 4083
![INFINITI QX56 2008 Factory Service Manual EC-412
< COMPONENT DIAGNOSIS >[VK56DE]
IGNITION SIGNAL
OK >>
INSPECTION END
NG >> GO TO 10.
4.CHECK IGNITION COIL POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF, wait at least 10 seconds and then INFINITI QX56 2008 Factory Service Manual EC-412
< COMPONENT DIAGNOSIS >[VK56DE]
IGNITION SIGNAL
OK >>
INSPECTION END
NG >> GO TO 10.
4.CHECK IGNITION COIL POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF, wait at least 10 seconds and then](/manual-img/42/57030/w960_57030-1710.png)
EC-412
< COMPONENT DIAGNOSIS >[VK56DE]
IGNITION SIGNAL
OK >>
INSPECTION END
NG >> GO TO 10.
4.CHECK IGNITION COIL POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
2. Check voltage between ECM terminals 119, 120 and ground with CONSULT-IIl or tester.
OK or NG
OK >> GO TO 5.
NG >> Go to EC-83
.
5.CHECK IGNITION COIL POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect condenser-1 harness connector.
3. Turn ignition switch ON.
4. Check voltage between condenser-1 terminal 1 and ground with CONSULT-IIl or tester.
OK or NG
OK >> GO TO 8.
NG >> GO TO 6.
6.CHECK IGNITION COIL POWER SUPPLY CIRCUIT-III
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R connector E119.
3. Check harness continuity between IPDM E/R terminal 4 and condenser-1 terminal 1. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> Go to EC-83.
NG >> GO TO 7.
7.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors E2, F32 Voltage: Battery voltage
MBIB0034E
BBIA0358E
Voltage: Battery voltage
PBIB0624E
Continuity should exist.
Revision: March 2010
2008 QX56