INFINITI QX56 2011 Factory Service Manual

P2135 TP SENSOREC-477
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Is the inspection result normal?
YES >> INSPECTION END
NO >> GO TO 2.
2.REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
Replace electric throttle control actuator. Refer to EM-30, "
Removal and Installation".
>> INSPECTION END
ECM Condition Voltage (V)
Connector +–
Terminal Terminal
F110 91
(TP sensor 1 signal) 97
(Sensor ground) Accelerator pedal Fully released More than 0.36
Fully depressed Less than 4.75
79
(TP sensor 2 signal) Fully released Less than 4.75
Fully depressed More than 0.36
Revision: 2010 May2011 QX56

EC-478
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P2138 APP SENSOR
P2138 APP SENSOR
DTC LogicINFOID:0000000006217981
DTC DETECTION LOGIC
NOTE:
If DTC P2138 is displayed with DTC P0643, first pe
rform the trouble diagnosis for DTC P0643. Refer to
EC-381, "
DTC 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, confi rm that battery voltage is 8 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and let it idle for 1 second.
2. Check DTC.
Is DTC detected?
YES >> Go to EC-478, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217982
1.CHECK ACCELERATOR PEDAL POSITION SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect accelerator pedal position (APP) sensor harness connector.
2. Turn ignition switch ON.
3. Check the voltage between APP sensor harness connector and ground.
Is the inspection result normal?
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P2138 APP SENSOR
(Accelerator pedal position
sensor circuit range/perfor-
mance) Rationally incorrect voltage is
sent to ECM compared with
the signals from APP sensor 1
and APP sensor 2.  Harness or connectors
(APP sensor 1 or 2 circuit is open or shorted.)
[CKP sensor circuit is shorted.]
[CMP sensor (bank 1) circuit is shorted.]
(Battery current sensor circuit is shorted.)
(Refrigerant pressure sensor circuit is shorted.)
(EVAP control system pressure sensor circuit is short-
ed.)
 Accelerator pedal position sensor (APP sensor 1 or 2)
 Crankshaft position sensor
 Camshaft position sensor (bank 1)
 Refrigerant pressure sensor
 Battery current sensor
 EVAP control system pressure sensor
APP sensor Ground Voltage (V)
Connector Terminal
E110
(Without ICC) 2
Ground Approx. 5
E67
(With ICC) 12
Revision: 2010 May2011 QX56

P2138 APP SENSOREC-479
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YES >> GO TO 3.
NO >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
 Loose or poor connection for each connector and harness
 Harness for open or short between ECM and APP sensor
>> Repair open circuit, short to ground or short to power in harness or connectors.
3.CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-I
1. Turn ignition switch ON.
2. Check the voltage between APP sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 8.
NO >> GO TO 4.
4.CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between APP sens or harness connector and ECM harness connector.
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 5.
5.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.
6.CHECK SENSOR POWER SUPPLY CIRCUIT
Check harness for short to power and short to ground, between the following terminals.
APP sensor
Ground Voltage (V)
Connector Terminal
E110
(Without ICC) 1
Ground Approx. 5
E67
(With ICC) 9
APP sensor ECM
Continuity
Connector Terminal Connector Terminal
E110
(Without ICC) 1
E80 131 Existed
E67
(With ICC) 9
ECM Sensor
Connector Terminal Name Connector Terminal
F110 76 Crankshaft position sensor F74 1
77 Camshaft position sensor (bank 1) F84 1
Revision: 2010 May2011 QX56

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

P2138 APP SENSOREC-481
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2. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 12.
NO >> GO TO 11.
11 .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.
12.CHECK APP SENSOR
Refer to EC-481, "
Component Inspection (Accelerator Pedal Position Sensor)".
Is the inspection result normal?
YES >> GO TO 14.
NO >> GO TO 13.
13.REPLACE ACCELERATOR PEDAL ASSEMBLY
Replace accelerator pedal assembly. Refer to ACC-3, "
MODELS WITHOUT DISTANCE CONTROL ASSIST
SYSTEM : Removal and Installation" (Without distance control assist system) or ACC-4, "MODELS WITH
DISTANCE CONTROL ASSIST SYSTEM : Removal and Installation" (With distance control assist system).
>> INSPECTION END
14.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (Accele rator Pedal Position Sensor)INFOID:0000000006217983
1.CHECK ACCELERATOR PEDAL POSITION SENSOR
1. Turn ignition switch OFF.
2. Reconnect all harness connectors disconnected.
3. Turn ignition switch ON.
4. Check the voltage ECM harness connector terminals under the following conditions.
Is the inspection result normal?
APP sensor ECM Continuity
Connector Terminal Connector Terminal
E110
(Without ICC) 3
E80 136
Existed
6126
E67
(With ICC) 10
E80 136
Existed
7126
ECM
Condition Voltage (V)
Connector +–
Te r m i n a l Te r m i n a l
E80 136 (APP sensor 1) 140
Accelerator pedalFully released 0.65 - 0.87
Fully depressed 4.3 - 4.8
126 (APP sensor 2) 129 Fully released 0.28 - 0.48
Fully depressed 2.0 - 2.5
Revision: 2010 May2011 QX56

EC-482
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P2138 APP SENSOR
YES >> INSPECTION END
NO >> GO TO 2.
2.REPLACE ACCELERATOR PEDAL ASSEMBLY
Replace accelerator pedal assembly. Refer to ACC-3, "
MODELS WITHOUT DISTANCE CONTROL ASSIST
SYSTEM : Removal and Installation" (Without distance control assist system) or ACC-4, "MODELS WITH
DISTANCE CONTROL ASSIST SYSTEM : Removal and Installation" (With distance control assist system).
>> INSPECTION END
Revision: 2010 May2011 QX56

P2539, P2541, P2542 LOW FUEL PRESSURE SENSOR
EC-483
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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

EC-484
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P2539, P2541, P2542 LOW
FUEL PRESSURE SENSOR
Is inspection result normal?
YES >> GO TO 4.
NO >> GO TO 3.
3.CHECK SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness connector for short to power and short to ground, between the following terminals.
Is inspection result normal?
YES >> Perform the trouble diagnosis for power supply circuit. Refer to EC-168, "Diagnosis Procedure".
NO >> Repair or replace error-detected parts.
4.CHECK LOW FUEL PRESSURE SENSOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between low fuel pressu re sensor harness connector and ECM harness connector.
Is inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace error-detected parts.
5.CHECK ECM GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between ECM harness connector and the ground.
Is inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
+
−Voltag e
(Approx.)
Low fuel pressure sensor
Connector Terminal F25 3 Ground 5 V
ECM Sensor
Connector Terminal Name Connector Terminal
F 111 27Power steering pressure sensor F35 1
Low fuel pressure sensor F25 3
Cooling fan speed sensor F39 2
28 FRP sensor F26 1
+ −
Continuity
Low fuel pressure sensor ECM
Connector Terminal Connector Terminal F25 1 F111 45 Existed
ECM Ground Continuity
Connector Terminal
F 111 5
Ground Existed
E80 11 4
11 5
174
175
Revision: 2010 May2011 QX56

P2539, P2541, P2542 LOW FUEL PRESSURE SENSOR
EC-485
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NO >> Repair or replace error-detected parts.
6.CHECK LOW FUEL PRESSURE SENSOR SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between low fuel pressu re sensor harness connector and ECM harness connector.
4. Also check harness for short to ground and to power.
Is inspection result normal?
YES >> GO TO 7.
NO >> Repair or replace error-detected parts.
7.CHECK LOW FUEL PRESSURE SENSOR
Refer to EC-485, "
Component Inspection".
Is inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
NO >> Replace low fuel pressure sensor.
Component InspectionINFOID:0000000006289706
1.CHECK LOW FUEL PRESSURE SENSOR
WITH CONSULT-III
1. Turn ignition switch OFF.
2. Reconnect harness connector disconnected.
3. Start the engine.
4. Select “DATA MONITOR” mode with CONSULT-III.
5. Check that the “L/FUEL PRES SEN V” value.
WITHOUT CONSULT-III
1. Turn ignition switch OFF.
2. Reconnect harness connector disconnected.
3. Start the engine.
4. Check low fuel pressure sensor signal voltage.
+ −
Continuity
Low fuel pressure sensor ECM
Connector Terminal Connector Terminal F25 2 F111 23 Existed
Data monitor item Condition Va l u e
(Approx.)
L/FUEL PRES SEN V Engine speed: idle
3,000 –3,300 mV
Engine speed: 3,000 rpm (no load)
Revision: 2010 May2011 QX56

EC-486
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P2539, P2541, P2542 LOW
FUEL PRESSURE SENSOR
Is the inspection result normal?
YES >> INSPECTION END.
NO >> Replace low fuel pressure sensor. Refer to EM-43, "
Removal and Installation".
+−
Condition Va l u e
(Approx.)
Low fuel pressure sensor
Ground
Connector Terminal
F25 2 Ground [Engine is running]
 Warm-up condition
 Idle speed
[Engine is running]
 Warm-up condition
 Engine speed: 2,000 rpm
JPBIA3357ZZ
JPBIA3358ZZ
Revision: 2010 May2011 QX56