sensor INFINITI QX56 2009 Factory Service Manual

EC-278
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P0550 PSP SENSOR
2.CHECK PSP SENSOR POWER SUPPLY CIRCUIT
1. Disconnect power steering pressure (PSP) sensor (1) harness connector.
2. Turn ignition switch ON.
3. Check voltage between PSP sensor terminal 1 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connectors.
3.CHECK PSP SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between PSP sensor terminal 3 and ECM terminal 67. Refer to Wiring Diagram.
4. 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 PSP SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 12 and PSP sensor terminal 2.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK PSP SENSOR
Refer to EC-279, "Component Inspection"
.
OK or NG
OK >> GO TO 6.
NG >> Replace PSP sensor.
6.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "How to Check Terminal"
and GI-38, "Intermittent Incident".
>> INSPECTION END
BBIA0741E
Voltage: Approximately 5V
PBIB0188E
Continuity should exist.
Continuity should exist.
Revision: December 20092009 QX56

P0550 PSP SENSOREC-279
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Component InspectionINFOID:0000000003771558
POWER STEERING PRESSURE SENSOR
1. Reconnect all harness connectors disconnected.
2. Start engine and let it idle.
3. Check voltage between ECM terminal 12 and ground under the
following conditions.
Condition Voltage
Steering wheel: Being turned. 0.5 - 4.5V
Steering wheel: Not being turned. 0.4 - 0.8V
MBIB0126E
Revision: December 20092009 QX56

P0643 SENSOR POWER SUPPLYEC-285
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P0643 SENSOR POWER SUPPLY
On Board Diagnosis LogicINFOID:0000000003771567
This self-diagnosis has the on
e trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM ent ers fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000003771568
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10V at idle.
1. Start engine and let it idle for 1 second.
2. Check DTC.
3. If DTC is detected, go to EC-285, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771569
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-85, "Ground Inspection"
.
OK or NG
OK >> GO TO 2.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0643
0643 Sensor power supply circuit
short ECM detects a voltage of power source
for sensor is excessively low or high.  Harness or connectors
(APP sensor 1 circuit is shorted.)
(PSP sensor circuit is shorted.)
(Battery current sensor circuit is shorted.)
(Refrigerant pressure se nsor circuit is short-
ed.)
(EVAP control system pressure sensor circuit
is shorted.)
 Accelerator pedal position sensor
 Power steering pressure sensor
 Refrigerant pressure sensor
 EVAP control system pressure sensor
Engine operation condition in fail-safe mode
ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) b y the return
spring.
BBIA0354E
Revision: December 20092009 QX56

EC-286
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P0643 SENSOR POWER SUPPLY
NG >> Repair or replace ground connections.
2.CHECK APP SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect accelerator pedal position (APP) sensor harness connector.
2. Turn ignition switch ON.
3. Check voltage between APP sensor terminal 7 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 3.
3.CHECK SENSOR POWER SUPPLY CIRCUITS
Check harness for short to power and short to ground, between the following terminals
OK or NG
OK >> GO TO 4.
NG >> Repair short to ground or short to power in harness or connectors.
4.CHECK COMPONENTS
Check the following.
 EVAP control system pressure sensor (Refer to EC-244, "Component Inspection"
.)
 Power steering pressure sensor (Refer to EC-279, "Component Inspection"
.)
 Battery current sensor (Refer to EC-310, "Component Inspection"
.)
 Refrigerant pressure sensor
OK or NG
OK >> GO TO 7.
NG >> Replace malfunctioning components.
5.CHECK ACCELERATOR PEDAL POSITION SENSOR
Refer to EC-376, "Component Inspection"
.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
BBIA0361E
Voltage: Approximately 5V
JMBIA0601ZZ
ECM terminal Sensor terminal Reference Wiring Diagram
48 EVAP control system pressure sensor terminal 3
EC-432, "Wiring Diagram - ENGINE
CONTROL SYSTEM -"
49Refrigerant pressure sensor terminal 1
Battery current sensor terminal 1
68 Power steering pressure sensor terminal 1
90 APP sensor terminal 7
Revision: December 20092009 QX56

P0643 SENSOR POWER SUPPLYEC-287
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6.REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace accelerator pedal position assembly.
2. Perform EC-18, "Accelerator Pedal Released Position Learning"
.
3. Perform EC-18, "Throttle Valve Closed Position Learning"
.
4. Perform EC-18, "Idle Air Volume Learning"
.
>> INSPECTION END
7.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "How to Check Terminal"
and GI-38, "Intermittent Incident".
>> INSPECTION END
Revision: December 20092009 QX56

P1140, P1145 IVT CONTROL POSITION SENSOR
EC-291
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P1140, P1145 IVT CONTROL POSITION SENSOR
Component DescriptionINFOID:0000000003771575
Intake valve timing control position sensors are located in the front of
cylinder heads in both bank 1 and bank 2.
This sensor uses a Hall IC.
The cam position is determined by the intake camshaft sprocket con-
cave (in four places). The ECM provides feedback to the intake valve
timing control for appropriate target valve open-close timing accord-
ing to drive conditions based on detected cam position.
On Board Diagnosis LogicINFOID:0000000003771576
DTC Confirmation ProcedureINFOID:0000000003771577
1. If DTC Confirmation Procedure has been previously c
onducted, always perform the following before con-
ducting the next step.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Turn ignition switch ON.
c. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-III.
4. Maintain the following conditions for at least 10 seconds.
5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to EC-291, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771578
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
SEF359Z
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1140
11 4 0
(Bank 1)
Intake valve timing control
position sensor circuit An excessively high or low voltage from the
sensor is sent to ECM.  Harness or connectors
(Intake valve timing control position
sensor circuit is open or shorted)
 Intake valve timing control position sensor
 Crankshaft position sensor (POS)
 Camshaft positi on sensor (PHASE)
 Accumulation of debris to the signal pick-up portion of the camshaft sprock-
et
P1145
11 4 5
(Bank 2)
ENG SPEED More th
an idle speed
Selector lever P or N position
Revision: December 20092009 QX56

EC-292
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P1140, P1145 IVT CONT
ROL POSITION SENSOR
Refer to EC-85, "Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK INTAKE VALVE TIMING CONTROL PO SITION SENSOR POWER SUPPLY CIRCUIT
1. Disconnect intake valve timing control position sensor harness connector.
2. Turn ignition switch ON.
3. Check voltage between intake valve timing control position sen- sor terminal 3 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
 Harness connectors E2, F32
 Harness for open or short between intake valve timing control position sensor and IPDM E/R
 Harness for open or short between intake va lve timing control position sensor and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK INTAKE VALVE TIMING CONTROL POSI TION SENSOR GROUND CIRCUIT FOR OPEN AND
SHORT
1. Turn ignition switch OFF.
2. Check harness continuity between intake valve timing control position sensor terminal 1 and ground.
Refer to Wiring Diagram.
BBIA0354E
1. Intake valve timing control position
sensor (bank 2) 2. Intake valve timing control solenoid
valve (bank 2) 3. Drive belt
4. Radiator hose 5. Intake valve timing control solenoid valve (bank 1)6. Intake valve timing control position
sensor (bank 1)
Voltage: Battery voltage
BBIA0771E
PBIB2613E
Revision: December 20092009 QX56

P1140, P1145 IVT CONTROL POSITION SENSOR
EC-293
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3. Also check harness for short to power.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
 Harness connectors E2, F32
 Harness for open or short between intake valve timing control position sensor and ground
>> Repair open circuit or short to power in harness or connectors.
6.CHECK INTAKE VALVE TIMING CONTROL POSIT ION SENSOR INPUT SIGNAL CIRCUIT FOR OPEN
AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between the following; ECM terminal 72 and intake valve timing control position sensor (Bank 1) terminal 2 or
ECM terminal 53 and intake valve timing contro l position sensor (Bank 2) terminal 2.
Refer to Wiring Diagram.
3. 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 INTAKE VALVE TIMING CONTROL POSITION SENSOR
Refer to EC-294, "Component Inspection"
.
OK or NG
OK >> GO TO 8.
NG >> Replace malfunctioning intake valve timing control position sensor. Refer to EC-493
.
8.CHECK CRANKSHAFT POSITION SENSOR (POS)
Refer to EC-200, "Component Inspection"
.
OK or NG
OK >> GO TO 9.
NG >> Replace crankshaft position sensor (POS).
9.CHECK CAMSHAFT POSITI ON SENSOR (PHASE)
Refer to EC-204, "Component Inspection"
.
OK or NG
OK >> GO TO 10.
NG >> Replace camshaft position sensor (PHASE). Refer to EC-493
.
10.CHECK CAMSHAFT SPROCKET
Check accumulation of debris to the signal pick- up portion of the camshaft sprocket. Refer to EM-62, "Inspec-
tion after Installation".
OK or NG
OK >> GO TO 11.
NG >> Remove debris and clean the signal pick-up cutout of camshaft sprocket.
11 .CHECK INTERMITTENT INCIDENT
Refer to GI-35, "How to Check Terminal"
and GI-38, "Intermittent Incident".
Continuity should exist.
Continuity should exist.
Revision: December 20092009 QX56

EC-294
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P1140, P1145 IVT CONT
ROL POSITION SENSOR
>>INSPECTION END
Component InspectionINFOID:0000000003771579
INTAKE VALVE TIMING CONTROL POSITION SENSOR
1. Disconnect intake valve timing control position sensor harness connector.
2. Loosen the fixing bolt of the sensor.
3. Remove the sensor.
4. Visually check the sensor for chipping.
5. Check resistance as shown below.
6. If NG, replace intake valve timing control position sensor. Refer
to EC-493
.
SEF362Z
Terminal No. (Polarity) Resistance Ω [at 25 °C (77 °F)]
3 (+) - 1 (-) Except 0 or ∞
2 (+) - 1 (-)
3 (+) - 2 (-)
JMBIA0600ZZ
Revision: December 20092009 QX56

P1148, P1168 CLOSED LOOP CONTROLEC-295
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P1148, P1168 CLOSED LOOP CONTROL
On Board Diagnosis LogicINFOID:0000000003771580
These self-diagnoses have the on
e trip detection logic.
DTC P1148 or P1168 is displayed with another DTC for air fuel ratio (A/F) sensor 1.
Perform the trouble diagnosis for the corresponding DTC.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1148
11 4 8
(Bank 1) Closed loop control
function The closed loop control function for bank 1 does
not operate even when vehicle is driving in the
specified condition.
 Harness or connectors
[The air fuel ratio (A/F) sensor 1 circuit is
open or shorted.]
 Air fuel ratio (A/F) sensor 1
 Air fuel ratio (A/F) sensor 1 heater
P1168
11 6 8
(Bank 2) The closed loop control function for bank 2 does
not operate even when vehicle is driving in the
specified condition.
Revision: December 20092009 QX56