2008 INFINITI QX56 ignition

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

ASCD BRAKE SWITCHEC-393
< COMPONENT DIAGNOSIS > [VK56DE]
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10.CHECK STOP LAMP SWITCH
Refer to EC-393, "
Component Inspection".
OK or NG
OK >> GO TO 11.
NG >> Replace stop lamp switch.
11 .CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000001365867
ASCD BRAKE SWITCH
1. Turn ignition switch OFF.
2. Disconnect ASCD brake switch harness connector.
3. Check harness continuity between ASCD brake switch terminals
1 and 2 under the following conditions.
If NG, adjust ASCD brake switch installation, refer to BR-15,
"Inspection and Adjustment", and perform step 3 again.
STOP LAMP SWITCH
1. Turn ignition switch OFF.
2. Disconnect stop lamp switch harness connector.
3. Check harness continuity between stop lamp switch terminals 3
and 4 under the following conditions.
If NG, adjust stop lamp switch installation, refer to BR-15,
"Inspection and Adjustment", and perform step 3 again.
ConditionContinuity
Brake pedal: Fully released Should exist.
Brake pedal: Slightly depressed Should not exist.
PBIB1536E
ConditionContinuity
Brake pedal: Fully released Should not exist.
Brake pedal: Slightly depressed Should exist.
PBIB2103E
Revision: March 2010 2008 QX56

EC-394
< COMPONENT DIAGNOSIS >[VK56DE]
ASCD INDICATOR
ASCD INDICATOR
Component DescriptionINFOID:0000000001365868
ASCD indicator lamp illuminates to indicate ASCD
operation status. Lamp has two indicators, CRUISE and
SET, and is integrated in combination meter.
CRUISE indicator illuminates when MAIN switch on ASCD st eering switch is turned ON to indicate that ASCD
system is ready for operation.
SET indicator illuminates when following conditions are met.
• CRUISE indicator is illuminated.
• SET/COAST switch on ASCD steering switch is turned ON while vehicle speed is within the range of ASCD setting.
SET indicator remains lit during ASCD control.
Refer to EC-33
for the ASCD function.
Diagnosis ProcedureINFOID:0000000001365871
1.CHECK OVERALL FUNCTION
Check ASCD indicator under the following conditions.
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
2.CHECK DTC
Check that DTC U1000 or U1001 is not displayed.
OK or NG
OK >> GO TO 3.
NG >> Perform trouble diagnosis for DTC U1000, U1001. Refer to EC-87
.
3.CHECK COMBINATION METER FUNCTION
Refer to MWI-5
.
OK or NG
OK >> GO TO 4.
NG >> Go to MWI-5
.
4.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
ASCD INDICATOR CONDITIONSPECIFICATION
CRUISE LAMP • Ignition switch: ON • MAIN switch: Pressed at the 1st
time → at the 2nd time ON
→ OFF
SET LAMP • MAIN switch: ON
• When vehicle speed is between
40 km/h (25 MPH) and 144 km/h
(89 MPH) • ASCD: Operating
ON
• ASCD: Not operating OFF
Revision: March 2010 2008 QX56

COOLING FANEC-395
< COMPONENT DIAGNOSIS > [VK56DE]
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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
Revision: March 2010
2008 QX56

ELECTRICAL LOAD SIGNALEC-397
< COMPONENT DIAGNOSIS > [VK56DE]
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ELECTRICAL LOAD SIGNAL
DescriptionINFOID:0000000001365872
The electrical load signal (Headlamp switch signal, r
ear window defogger switch signal, etc.) is transferred
through the CAN communication line from BCM to ECM via IPDM E/R.
Diagnosis ProcedureINFOID:0000000001365874
1.CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-I
1. Turn ignition switch ON.
2. Connect CONSULT-IIl and select “DATA MONITOR” mode.
3. Select “LOAD SIGNAL” and check indication under the following conditions.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
2.CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-II
Check “LOAD SIGNAL” indication under the following conditions.
OK or NG
OK >> GO TO 3.
NG >> GO TO 5.
3.CHECK HEATER FAN SIGNAL CIRCUIT OVERALL FUNCTION
Select “HEATER FAN SW” and check indication under the following conditions.
OK or NG
OK >> INSPECTION END
NG >> GO TO 6.
4.CHECK REAR WINDOW DEFOGGER SYSTEM
Refer to DEF-4
.
>> INSPECTION END
5.CHECK HEADLAMP SYSTEM
Refer to EXL-7
, or EXL-9.
>> INSPECTION END
6.CHECK HEATER FAN CONTROL SYSTEM
Refer to HAC-49
.
Condition Indication
Rear window defogger switch: ON ON
Rear window defogger switch: OFF OFF
ConditionIndication
Lighting switch: ON at 2nd position ON
Lighting switch: OFF OFF
ConditionIndication
Heater fan control switch: ON ON
Heater fan control switch: OFF OFF
Revision: March 2010 2008 QX56

FUEL INJECTOREC-399
< COMPONENT DIAGNOSIS > [VK56DE]
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FUEL INJECTOR
Component DescriptionINFOID:0000000001365875
The fuel injector is a small, precise solenoid valve. When the ECM
supplies a ground to the fuel injector circuit, the coil in the fuel injec-
tor is energized. The energized coil pulls the ball valve back and
allows fuel to flow through the fuel injector into the intake manifold.
The amount of fuel injected depends upon the injection pulse dura-
tion. Pulse duration is the length of time the fuel injector remains
open. The ECM controls the injection pulse duration based on
engine fuel needs.
Diagnosis ProcedureINFOID:0000000001365878
1.INSPECTION START
Turn ignition switch to START.
Is any cylinder ignited?
Ye s o r N o
Yes >> GO TO 2.
No >> GO TO 3.
2.CHECK OVERALL FUNCTION
With CONSULT-IIl
1. Start engine.
2. Perform “POWER BALANCE” in “A CTIVE TEST” mode with CONSULT-IIl.
3. Make sure that each circuit produces a momentary engine speed drop.
Without CONSULT-IIl
1. Start engine.
2. Listen to each fuel injector operating sound.
Clicking noise should be heard.
OK or NG
OK >> INSPECTION END
NG >> GO TO 3.
3.CHECK FUEL INJECTOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
SEF375Z
PBIB1986E
Revision: March 2010 2008 QX56

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
2008 QX56

EC-402
< COMPONENT DIAGNOSIS >[VK56DE]
FUEL PUMP
FUEL PUMP
DescriptionINFOID:0000000001365881
SYSTEM DESCRIPTION
*: ECM determines the start signal status by the signals of engine speed and battery voltage.
The ECM activates the fuel pump for several seconds after the ignition switch is turned ON to improve engine
startability. If the ECM receives a engine speed signal
from the camshaft position sensor (PHASE), it knows
that the engine is rotating, and causes the pump to operate. If the engine speed signal is not received when
the ignition switch is ON, the engine stalls. The EC M stops pump operation and prevents battery discharging,
thereby improving safety. The ECM does not directly drive the fuel pump. It controls the ON/OFF fuel pump
relay, which in turn controls the fuel pump.
COMPONENT DESCRIPTION
A turbine type design fuel pump is used in the fuel tank.
Diagnosis ProcedureINFOID:0000000001365884
1.CHECK OVERALL FUNCTION
1. Turn ignition switch ON.
2. Pinch fuel feed hose with two fingers.
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
2.CHECK FUEL PUMP POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Turn ignition switch ON.
Sensor Input signal to ECMECM FunctionActuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed*
Fuel pump control Fuel pump relay
Battery Battery voltage*
Condition Fuel pump operation
Ignition switch is turned to ON. Operates for 1 second.
Engine running and cranking Operates.
When engine is stopped Stops in 1.5 seconds.
Except as shown above Stops.
BBIA0402E
Fuel pressure pulsation should be felt on the fuel feed
hose for 1 second after igniti on switch is turned ON.
BBIA0357E
Revision: March 2010 2008 QX56