2011 INFINITI QX56 BATTERY CONNECTORS

EC-460
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P2101 ELECTRIC THROTTLE CONTROL FUNCTION
P2101 ELECTRIC THROTTL
E CONTROL FUNCTION
DescriptionINFOID:0000000006217962
Electric throttle control actuator consists of th rottle control motor, throttle position sensor, etc.
The throttle control motor is operated by the ECM and it opens and closes the throttle valve.
The current opening angle of the throttle valve is detected by the throttle position sensor and it provides feed-
back to the ECM. ECM controls the throttle valve openi ng angle in response to driving condition via the throttle
control motor.
DTC LogicINFOID:0000000006217963
DTC DETECTION LOGIC
NOTE:
 If DTC P2101 is displayed with DTC P2100, first pe rform the trouble diagnosis for DTC P2100. Refer
to EC-458, "
DTC Logic".
 If DTC P2101 is displayed with DTC P2119, first pe rform the trouble diagnosis for DTC P2119. Refer
to EC-466, "
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, confirm that battery voltage is 11 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON and wait at least 2 seconds.
2. Start engine and let it idle for 5 seconds.
3. Check DTC.
Is DTC detected?
YES >> Go to EC-460, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217964
1.CHECK THROTTLE CONTROL MOTOR RELAY INPUT SIGNAL CIRCUIT-I
1. Check the voltage between ECM harness connector and ground under the following conditions.
Is the inspection result normal?
YES >> GO TO 8.
NO >> GO TO 2.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P2101 Electric throttle control
performance Electric throttle control function does not
operate properly.  Harness or connectors
(Throttle control motor circuit is open or shorted)
 Electric throttle control actuator
ECM Ground Condition Voltage
Connector Terminal
E80 173 Ground Ignition switch:
OFF
Approx. 0 V
Ignition switch:
ON Battery voltage
Revision: 2010 May2011 QX56

EC-468
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P2122, P2123 APP SENSOR
P2122, P2123 APP SENSOR
DTC LogicINFOID:0000000006217972
DTC DETECTION LOGIC
NOTE:
If DTC P2122 or P2123 is displayed with DTC P
0643, perform 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-468, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217973
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?
YES >> GO TO 3.
NO >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between ECM and APP sensor
 Loose or poor connection for each connector and harness
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P2122 APP SEN 1/CIRC
(Accelerator pedal position
sensor 1 circuit low input) An excessively low voltage from the APP
sensor 1 is sent to ECM.
 Harness or connectors
(APP sensor 1 circuit is open or shorted.)
 Accelerator pedal position sensor (APP sensor 1)
P2123 APP SEN 1/CIRC
(Accelerator pedal position
sensor 1 circuit high input) An excessively high voltage from the APP
sensor 1 is sent to ECM.
APP sensor
Ground Voltage (V)
Connector Terminal
E110
(Without ICC) 2
Ground Approx. 5
E67
(With ICC) 12
Revision: 2010 May2011 QX56

P2127, P2128 APP SENSOREC-471
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P2127, P2128 APP SENSOR
DTC LogicINFOID:0000000006217975
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, 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-471, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217976
1.CHECK ACCELERATOR PEDAL POSITION SENSOR 2 POWER SUPPLY CIRCUIT-I
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?
YES >> GO TO 6.
NO >> GO TO 2.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P2127 APP SEN 2/CIRC
(Accelerator pedal position
sensor 2 circuit low input) An excessively low voltage from
the APP sensor 2 is sent to ECM.  Harness or connectors
(Accelerator pedal position sensor 2 circuit is open or
shorted.)
(Battery current sensor circuit is shorted.)
[Camshaft position sensor (bank 1) circuit is shorted.]
(Crankshaft position sensor circuit is shorted.)
(Refrigerant pressure sensor circuit is shorted.)
(EVAP control system pres sure sensor circuit is
shorted.)
 Accelerator pedal position sensor (APP sensor 2)
 Battery current sensor
 Camshaft position sensor (bank 1)
 Crankshaft position sensor
 Refrigerant pressure sensor
 EVAP control system pressure sensor
P2128
APP SEN 2/CIRC
(Accelerator pedal position
sensor 2 circuit high input) An excessively high voltage from
the APP sensor 2 is sent to ECM.
APP sensor
Ground Voltage (V)
Connector Terminal
E110
(Without ICC) 1
Ground Approx. 5
E67
(With ICC) 9
Revision: 2010 May2011 QX56

EC-472
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P2127, P2128 APP SENSOR
2.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 4.
NO >> GO TO 3.
3.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.
4.CHECK SENSOR POWER SUPPLY CIRCUIT
Check harness for short to power and short to ground, between the following terminals.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair short to ground or short to power in harness or connectors.
5.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 12.
NO >> Replace malfunctioning component.
6.CHECK APP SENSOR 2 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.
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
E80 133Battery current sensor E63 2
Refrigerant pressure sensor E77 1
EVAP control system pressure sensor C17 3
131 APP sensor (Without ICC) E110 1
APP sensor (with ICC) E67 9
Revision: 2010 May2011 QX56

P2135 TP SENSOREC-475
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P2135 TP SENSOR
DTC LogicINFOID:0000000006217978
DTC DETECTION LOGIC
NOTE:
If DTC P2135 is displayed with DTC P0643, perfo
rm 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-475, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217979
1.CHECK THROTTLE POSITION SEN SOR POWER SUPPLY CIRCUIT-I
1. Disconnect electric throttle c ontrol actuator harness connector.
2. Turn ignition switch ON.
3. Check the voltage between electric throttle control actuator harness connector and ground.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
2.CHECK THROTTLE POSITI ON SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between electric throttle control actuator harness connector and ECM harness con-
nector.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P2135 TP SENSOR-B1
(Throttle position sensor circuit
range/performance) Rationally incorrect voltage is sent to
ECM compared with the signals from
TP sensor 1 and TP sensor 2.  Harness or connector
(TP sensor 1 or 2 circuit is open or shorted.)
 Electric throttle control actuator
(TP sensor 1 or 2)
Electric throttle control actuator Ground Voltage (V)
Connector Terminal
F66 2 Ground Approx. 5
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

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