2011 INFINITI QX56 BATTERY

EC-480
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P2138 APP SENSOR
Is the inspection result normal?
YES >> GO TO 7.
NO >> Repair short to ground or short to power in harness or connectors.
7.CHECK COMPONENTS
Check the following.
 Crankshaft position sensor (Refer to EC-301, "
Component Inspection (Crankshaft Position Sensor)".)
 Camshaft position sensor (bank 1) (Refer to EC-306, "
Component Inspection (Camshaft Position Sensor)".)
 Refrigerant pressure sensor (Refer to EC-520, "
Component Function Check".)
 EVAP control system pressure sensor (Refer to EC-335, "
Component Inspection (EVAP Control System
Pressure Sensor)".)
Is the inspection result normal?
YES >> GO TO 14.
NO >> Replace malfunctioning component.
8.CHECK APP SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between APP sens or harness connector and ECM harness connector.
4. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 10.
NO >> GO TO 9.
9.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between ECM and accelerator pedal position sensor
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
10.CHECK APP SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check the continuity between APP sens or harness connector and ECM harness connector.
E80133Battery current sensor E63 2
Refrigerant pressure sensor E77 1
EVAP control system pressure sen-
sor
C17 3
131 APP sensor (Without ICC) E110 1
APP sensor (with ICC) E67 9
ECM Sensor
Connector Terminal Name Connector Terminal
APP sensor ECM Continuity
Connector Terminal Connector Terminal
E110
(Without ICC) 4
E80 140
Existed
5129
E67
(With ICC) 11
E80 140
Existed
8129
Revision: 2010 May2011 QX56

P2539, P2541, P2542 LOW FUEL PRESSURE SENSOR
EC-483
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P2539, P2541, P2542 LOW
FUEL PRESSURE SENSOR
DTC LogicINFOID:0000000006288355
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is 11 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and let it idle for at least 60 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-483, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288356
1.CHECK LOW FUEL PRESSURE SENSOR POWER SUPPLY-I
1. Turn ignition switch OFF.
2. Disconnect low fuel pressure sensor connector.
3. Turn ignition switch ON.
4. Check the voltage between low fuel pressure sensor harness connector terminals.
Inspection result normal?
YES >> GO TO 6.
NO >> GO TO 2.
2.CHECK LOW FUEL PRESSURE SENSOR POWER SUPPLY-II
Check the voltage between low fuel pressure sensor harness connector and the ground.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P2539 LOW FUEL PRES SEN
(Low fuel pressure sensor
circuit low input and high in-
put) Signal voltage from the low fuel pressure
sensor remains at more than 4.84 V / less
than 0.3 V for 5 seconds or more.  Harness or connectors
(Low fuel pressure sensor circuit is open
or shorted.)
(Power steering pressure sensor circuit is
open or shorted.)
(Cooling fan speed sensor circuit is open
or shorted.)
(FRP sensor circuit is open or shorted.)
 Low fuel pressure sensor
 Power steering pressure sensor
 Cooling fan speed sensor
 FRP sensor
P2541
LOW FUEL PRES SEN
(Low fuel pressure sensor
circuit low input) Signal voltage from the low fuel pressure
sensor remains at less than 0.49 V for 5 sec-
onds or more.
P2542 LOW FUEL PRES SEN
(Low fuel pressure sensor
circuit high input) Signal voltage from the low fuel pressure
sensor remains at more than 4.1 V for 5 sec-
onds or more.
Low fuel pressure sensor
Vo l ta g e
(Approx.)
Connector +
−
terminal
F25 3 1 5 V
Revision: 2010 May2011 QX56

P2A00, P2A03 A/F SENSOR 1EC-487
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P2A00, P2A03 A/F SENSOR 1
DTC LogicINFOID:0000000006217987
DTC DETECTION LOGIC
To judge the malfunction, the A/F signal computed by ECM fr
om the A/F sensor 1 signal is monitored so it will
not shift to LEAN side or RICH side.
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is 11 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Clear the mixture ratio self-learning value. Refer to EC-152, "
Work Procedure".
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Start engine and keep the engine speed between 3,500 and 4,000 rpm for 1 minute under no load.
6. Let engine idle for 1 minute.
7. Keep engine speed between 2,500 and 3,000 rpm for 20 minutes.
8. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-487, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217988
1.RETIGHTEN A/F SENSOR 1
Loosen and retighten the A/F sensor 1. Refer to EX-5, "
Exploded View".
>> GO TO 2.
2.CHECK A/F SENSOR 1 CONNECTOR
1. Disconnect A/F sensor 1 harness connector.
2. Check that water is not inside connectors.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace harness connector.
3.CHECK FOR INTAKE AIR LEAKAGE
1. Reconnect A/F sensor 1 harness connector.
2. Start engine and run it at idle.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P2A00 A/F SENSOR1 (B1)
(Air fuel ratio (A/F) sensor 1 (bank 1)
circuit range/performance)  The output voltage computed by ECM from
the A/F sensor 1 signal shifts to the lean side
for a specified period.
 The A/F signal computed by ECM from the
A/F sensor 1 signal shifts to the rich side for
a specified period.  A/F sensor 1
 A/F sensor 1 heater
 Fuel pressure
 Fuel injector
 Intake air leaks
P2A03 A/F SENSOR1 (B2)
(Air fuel ratio (A/F) sensor 1 (bank 2)
circuit range/performance)
Revision: 2010 May2011 QX56

EC-490
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
ASCD BRAKE SWITCH
ASCD BRAKE SWITCH
Component Function CheckINFOID:0000000006217989
1.CHECK ASCD BRAKE SWITCH FUNCTION
WITH CONSULT-III
1. Turn ignition switch ON.
2. Select “BRAKE SW1” in “DAT A MONITOR” mode with CONSULT-III.
3. Check “BRAKE SW1” indication under the following conditions.
WITHOUT CONSULT-III
1. Turn ignition switch ON.
2. Check the voltage between ECM harness connector terminals as per the following.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-490, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006217990
1.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 the voltage between ASCD brake switch harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
 10 A fuse (No. 3)
 Harness for open or short between ASCD brake switch and fuse
 Loose or poor connection for each connector and harness
>> Repair open circuit or short to ground in harness or connectors.
3.CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between ASCD brake s witch harness connector and ECM harness connector.
Monitor item Condition Indication
BRAKE SW1
(ASCD brake switch) Brake pedalSlightly depressed OFF
Fully released ON
ECM Condition Voltage (V)
Connector +–
Te r m i n a l Te r m i n a l
E80 147
(ASCD brake switch signal) 175 Brake pedalSlightly depressed Approx. 0
Fully released Battery voltage
ASCD brake switch
Ground Voltage
Connector Terminal
E109 1 Ground Battery voltage
Revision: 2010 May2011 QX56

ELECTRICALLY-CONTROLLED COOLING FAN COUPLINGEC-495
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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ELECTRICALLY-CONTROLLED COOLING FAN COUPLING
Component Function CheckINFOID:0000000006217997
1.CHECK COOLING FAN FUNCTION
WITH CONSULT-III
1. Start the engine.
2. Perform “FAN DUTY CONTROL” in “ACTIVE TEST” mode with CONSULT-III.
3. Check that cooling fan speed varies according to the percentage.
NOTE:
Speed changes gradually as the percentage changes.
WITHOUT CONSULT-III
1. Start the engine and warm up the engine until engine coolant temperature reaches at least 98°C (209 °F).
2. Check that cooling fan speed increase.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Proceed to EC-495, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006217998
1.CHECK DRIVE BELT
1. Turn ignition switch OFF.
2. Check that the drive belt is not broken.
Is inspection result normal?
YES >> GO TO 2.
NO >> Replace drive belt.
2.CHECK ELECTRICALLY-CONTROLLED COOLING FAN COUPLING POWER SUPPLY
1. Disconnect electrically-controlled c ooling fan coupling harness connector.
2. Turn ignition switch ON.
3. Check the voltage between electrically-controll ed cooling fan coupling harness connector and ground.
Is inspection result normal?
YES >> GO TO 3.
NO >> Perform trouble diagnosis for power supply circuit.
3.CHECK ELECTRICALLY-CONTROLLED COOLING FAN COUPLING GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check the continuity between electrically-cont rolled cooling fan coupling harness connector and ground.
Is inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace error-detected parts.
4.CHECK ELECTRICALLY-CONTROLLED COOLING FAN COUPLING CONTROL SIGNAL
WITH CONSULT-III
+ −Vo l ta g e
(Approx.)
Electrically-controlled cooling fan coupling
Connector TerminalF39 1 Ground Battery voltage
+ −Continuity
Electrically-controlled cooling fan coupling
Connector TerminalF39 6 Ground Existed
Revision: 2010 May2011 QX56

EC-498
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
FUEL INJECTOR
FUEL INJECTOR
Component Function CheckINFOID:0000000006218002
1.INSPECTION START
Turn ignition switch to START.
Are any cylinders ignited?
YES >> GO TO 2.
NO >> Proceed to EC-498, "
Diagnosis Procedure".
2.CHECK FUEL INJECTOR FUNCTION
WITH CONSULT-III
1. Start engine.
2. Perform “POWER BALANCE” in “A CTIVE TEST” mode with CONSULT-III.
3. Check that each circuit produces a momentary engine speed drop.
WITHOUT CONSULT-III
1. Start engine.
2. Listen to each fuel injector operating sound.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Proceed to EC-498, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006218003
1.CHECK FUEL INJECTOR POWER SUPPLY
1. Turn ignition switch ON.
2. Check the voltage between ECM harness connector and ground.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Perform the trouble diagnosis for power supply circuit. Refer to EC-168, "
Diagnosis Procedure".
2.CHECK FUEL INJECTOR CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect fuel injector harness connector and ECM harness connector.
3. Check the continuity between fuel inje ctor harness connector and ECM harness connector.
Clicking sound should be heard.
PBIB3332E
+
−Voltag e
ECM
Connector Terminal
F 111 46
Ground Battery voltage
51
E80 111
11 2
Revision: 2010 May2011 QX56

HIGH PRESSURE FUEL PUMPEC-501
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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HIGH PRESSURE FUEL PUMP
Component Function CheckINFOID:0000000006218005
1.CHECK HIGH PRESSURE FUEL PUMP FUNCTION
WITH CONSULT-III
1. Start engine.
2. Check “FUEL PRES SEN V” in “D ATA MONITOR” mode with CONSULT-III.
WITHOUT CONSULT-III
1. Start engine.
2. Check the voltage between ECM harness connector and ground.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Proceed to EC-501, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006218006
1.CHECK HIGH PRESSURE FUEL PUMP SOLENOID CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector and high pressure fuel pump harness connector.
3. Check the continuity between ECM harness connector and high pressure fuel pump harness connector.
Monitor Item Condition Values/Status
FUEL PRES SEN V Engine speed: Idle 980 – 1,200 mV
Engine speed: Revving engine from idle to 4,000 rpm
quickly
1,100 – 2,900 mV
ECM
Condition Voltage
+ −
Connector Terminal Connector Terminal
F110 105 E80 175 [Engine is running]
 Warm-up condition
 Idle speed
NOTE:
The pulse cycle changes depending
on rpm at idle BATTERY VOLTAGE
(11 - 14 V)
[Engine is running]
 Warm-up condition
 Engine speed: 2,000 rpm BATTERY VOLTAGE
(11 - 14 V)
JPBIA3340ZZ
JPBIA3341ZZ
+
−
Continuity
ECM High pressure fuel pump
Connector Terminal Connector Terminal
F110 105
F24 1
Existed
11 0 2
Revision: 2010 May2011 QX56

ICC BRAKE SWITCHEC-503
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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ICC BRAKE SWITCH
Component Function CheckINFOID:0000000006218008
1.CHECK ICC BRAKE SWITCH FUNCTION
WITH CONSULT-III
1. Turn ignition switch ON.
2. Select “BRAKE SW1” in “DATA MONITOR” mode with CONSULT-III.
3. Check “BRAKE SW1” indication under the following conditions.
WITHOUT CONSULT-III
1. Turn ignition switch ON.
2. Check the voltage between ECM harness connector terminals as per the following.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-503, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006218009
1.CHECK DTC WITH ADAS CONTROL UNIT
Refer to DAS-21, "
CONSULT-III Function (ICC/ADAS)" and DAS-38, "DTC Index".
Are any DTCs detected?
YES >> Perform the Diagnosis Procedur e corresponding to the detected DTC.
NO >> GO TO 2.
2.CHECK OVERALL FUNCTION
WITH CONSULT-III
1. Turn ignition switch ON.
2. Select “BRAKE SW1” in “DATA MONITOR” mode with CONSULT-III.
3. Check “BRAKE SW1” indication under the following conditions.
WITHOUT CONSULT-III
1. Turn ignition switch ON.
2. Check the voltage between ECM harness connector terminals under the following conditions.
Monitor item Condition Indication
BRAKE SW1
(ICC brake switch) Brake pedalSlightly depressed OFF
Fully released ON
ECM
Condition Voltage
Connector +–
Terminal Terminal
E80 147
(ICC brake switch signal) 175 Brake pedalSlightly depressed Approx. 0 V
Fully released Battery voltage
Monitor item Condition Indication
BRAKE SW1
(ICC brake switch) Brake pedalSlightly depressed OFF
Fully released ON
Revision: 2010 May2011 QX56