air condition INFINITI QX56 2011 Factory Service Manual

P0550 PSP SENSOREC-373
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NO >> Repair or replace error-detected parts.
6.CHECK PSP SENSOR SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between PSP sens or harness connector and ECM harness connector.
4. Also check harness for short to ground and to power.
Is the inspection result normal?
YES >> GO TO 7.
NO >> Repair or replace error-detected parts.
7.CHECK PSP SENSOR
Refer to EC-373, "
Component Inspection (Power Steering Pressure Sensor)".
Is the inspection result normal?
YES >> GO TO 8.
NO >> Replace PSP sensor.
8.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (Power Steering Pressure Sensor)INFOID:0000000006217872
1.CHECK POWER STEERING PRESSURE SENSOR
1. Turn ignition switch OFF.
2. Reconnect all harness connectors disconnected.
3. Start engine and let it idle.
4. Check the voltage between ECM harness connector terminals under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace power steering pressure sensor.
+ −
Continuity
PSP sensor ECM
Connector Terminal Connector Terminal F35 2 F111 39 Existed
ECM Condition Voltage (V)
Connector +–
Te r m i n a l Te r m i n a l
F111 39 45 Steering wheel Being turned 0.5 - 4.5
Not being turned 0.4 - 0.8
Revision: 2010 May2011 QX56

EC-374
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P0603 ECM POWER SUPPLY
P0603 ECM POWER SUPPLY
DTC LogicINFOID:0000000006217873
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.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON wait at least 10 seconds.
2. Turn ignition switch OFF and wait at least 5 minutes.
3. Turn ignition switch ON, wait at least 10 seconds.
4. Repeat step 2 and 3 for five times.
5. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-374, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217874
1.CHECK ECM POWER SUPPLY
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the voltage between ECM harness connector terminals.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
 20 A fuse (No. 43)
 Harness for open or short between ECM and battery
 Loose or poor connection for each connector and harness
>> Repair or replace harness or connectors.
3.CHECK INTERMITTENT INCIDENT
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0603 ECM BACK UP/CIRCUIT
(ECM power supply circuit) ECM back up RAM system does not
function properly.  Harness or connectors
[ECM power supply (back up) circuit is open or
shorted.]
ECM
ECM
Vol tag e
+–
Connector Terminal Connector Terminal E80 156 E80 175 Battery voltage
Revision: 2010 May2011 QX56

EC-380
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P062B ECM
P062B ECM
DescriptionINFOID:0000000006217879
This DTC is detected when the ECM-integrated injector dr
iver unit has a malfunction. For injector driver unit,
refer to EC-23, "
ECM".
DTC LogicINFOID:0000000006217880
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 the engine and keep the engine speed at idle for 30 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-380, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217881
1.CHECK FUEL INJECTOR
Perform fuel injector. Refer to EC-498, "
Component Function Check".
Is inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace error-detected parts.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Erase DTC.
3. Perform DTC cfirmation procedure again. Refer to EC-380, "
DTC Logic".
4. Check 1st trip DTC.
Is the DTC P062B displayed again?
YES >> Replace ECM. Refer to EC-535, "Removal and Installation".
NO >> INSPECTION END
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P062B Internal control module fuel injector
control performance Injector driver unit is malfunctioning.  Harness and connectors
(Injector circuit is open or
shorted)
 Battery power supply
 ECM (injector driver unit)
Revision: 2010 May2011 QX56

EC-384
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P0850 PNP SWITCH
4. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to
EC-384, "Diagnosis Procedure".
NO >> INSPECTION END
5.PERFORM COMPONENT FUNCTION CHECK
WITH GST
Perform Component Function Check. Refer to EC-384, "
Component Function Check".
NOTE:
Use Component Function Check to check the overall func tion of the park/neutral position (PNP) signal circuit.
During this check, a 1st trip DTC might not be confirmed.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-384, "
Diagnosis Procedure".
Component Function CheckINFOID:0000000006217886
1.PERFORM COMPONENT FUNCTION CHECK
WITH GST
1. Turn ignition switch ON.
2. Check the voltage between ECM harness connector terminals under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-384, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006217887
1.CHECK DTC WITH TCM
Refer to TM-61, "
CONSULT-III Function (TRANSMISSION)".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace malfunctioning part.
2.CHECK STARTING SYSTEM
Turn ignition switch OFF, then turn it to START.
Does starter motor operate?
YES >> GO TO 3.
NO >> Check DTC with BCM. Refer to BCS-57, "
DTCIndex".
3.CHECK PNP SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect A/T assembly harness connector.
3. Disconnect ECM harness connector.
4. Check the continuity between A/T assembly harness connector and ECM harness connector.
VHCL SPEED SE More than 64 km/h (40 mph)
Selector lever Suitable position
ECM
Condition Voltage (V)
Connector +–
Te r m i n a l Te r m i n a l
F111 11 175 Selector lever P or N position Battery voltage
Except above position Approx. 0
Revision: 2010 May2011 QX56

P1091 VVEL ACTUATOR MOTOR RELAYEC-393
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P1091 VVEL ACTUATOR MOTOR RELAY
DTC LogicINFOID:0000000006217900
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 10 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON and wait at least 1 seconds.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and wait at least 1 seconds.
4. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-393, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217901
1.VVEL ACTUATOR MOTOR RELAY POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF.
2. Disconnect VVEL actuator motor relay.
3. Check the voltage between VVEL actuator motor relay harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
 50A fusible link (letter O)
 Harness for open or short between VVEL actuator motor relay and battery
>> Repair open circuit, short to ground or short to power in harness or connectors.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P1091 VVEL ACTR MOT PWR
[VVEL actuator motor relay
circuit]  VVEL control module detects the VVEL
actuator motor relay is stuck OFF.
 VVEL control module detects the VVEL actuator motor relay is stuck ON.  Harness or connectors
(VVEL actuator motor rela y circuit is open or
shorted.)
(Abort circuit is open or shorted.)
 VVEL actuator motor relay
 VVEL control module
ECM
VVEL actuator motor relay Ground Voltage
Connector Terminal
E62 1
Ground Battery voltage
3
Revision: 2010 May2011 QX56

P1091 VVEL ACTUATOR MOTOR RELAYEC-395
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Is the inspection result normal?
YES >> GO TO 9.
NO >> Repair or replace.
9.REPLACE VVEL CONTROL MODULE
1. Replace VVEL control module.
2. Perform additional service when replacing VVEL control module. Refer to EC-144, "
Work Procedure".
>> GO TO 10.
10.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Erase DTC.
3. Perform DTC Confirmation Procedure. See EC-393, "
DTC Logic".
Is the DTC P1091 displayed again?
YES >> Replace ECM. Refer to EC-535, "Removal and Installation".
NO >> INSPECTION END
Component Inspection (VVE L Actuator Motor Relay)INFOID:0000000006217902
1.CHECK VVEL ACTUATOR MOTOR RELAY
1. Turn ignition switch OFF.
2. Remove VVEL actuator motor relay.
3. Check the continuity between VVEL actuator motor relay termi- nals under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace VVEL actuator motor relay.
Terminal Condition Continuity 3 and 5 12V direct current supply between
terminals 1 and 2
Existed
No current supply Not existed
JMBIA0876ZZ
Revision: 2010 May2011 QX56

P1212 TCS COMMUNICATION LINEEC-399
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P1212 TCS COMMUNICATION LINE
DescriptionINFOID:0000000006217906
This CAN communication line is used to control the
smooth engine operation during the TCS operation. Pulse
signals are exchanged between ECM and “ABS actuator and electric unit (control unit)”.
Be sure to erase the malfunction information such as DTC not only fo r “ABS actuator and electric unit
(control unit)” but also for ECM after TCS related repair.
DTC LogicINFOID:0000000006217907
DTC DETECTION LOGIC
NOTE:
 If DTC P1212 is displayed with DTC UXXXX, perform the trouble diagnosis for DTC UXXXX.
 If DTC P1212 is displayed with DTC P0607, perform the trouble diagnosis for DTC P0607.
Freeze frame data is not stored in the ECM for this self-diagnosis.
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 10.5 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and let it idle for at least 10 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-399, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217908
Perform the trouble diagnosis for TCS. Refer to BRC-60, "Work Flow".
NOTE:
If DTC P1212 is displayed with DTC UXXXX and/or P0607, perform the following trouble diagnosis.
 Trouble diagnosis for DTC UXXXX Refer to EC-98, "
DTC Index".
 Trouble diagnosis for DTC P0607 Refer to EC-378, "
DTC Logic".
DTC No.Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P1212 TCS/CIRC
(TCS communication line) ECM cannot receive the information from
“ABS actuator and electric unit (control
unit)” continuously.  Harness or connectors
(The CAN communication line is open or short-
ed.)
 ABS actuator and electric unit (control unit)
 Dead (Weak) battery
Revision: 2010 May2011 QX56

P1220 FUEL PUMP CONTROL MODULE (FPCM)
EC-403
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P1220 FUEL PUMP CONTROL MODULE (FPCM)
DTC LogicINFOID:0000000006217912
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 between 12 - 15 V at idle.
 Before performing the following procedure, check that the engine coolant temperature is −10 °C
(14 °F) or more.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and let it idle for at least 5 seconds. If engine does not start, crank engine for at least 5 seconds.
2. Check DTC.
Is DTC detected?
YES >> Go to EC-403, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217913
1.CHECK FPCM POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect FPCM harness connector.
3. Turn ignition switch ON.
4. Check the voltage between FPCM harness connector and ground.
Is the inspection result normal?
YES >> GO TO 2.
NO >> GO TO 3.
2.DETECT MALFUNCTIONING PART
Check the following.
 15 A fuse (No.73)
 Harness for open or short between FPCM and IPDM E/R
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P1220 FPCM
(Fuel pump control module) During engine cranking, the signal voltage
of the FPCM to the ECM is too low.  Harness or connectors
(FPCM circuit is open or shorted)
(Fuel pump circuit is open or shorted)
FPCM
FPCM Ground Voltage
Connector Terminal
B41 10 Ground Battery voltage
Revision: 2010 May2011 QX56

EC-406
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P1225 TP SENSOR
P1225 TP SENSOR
DTC LogicINFOID:0000000006217915
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 10 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-406, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217916
1.CHECK ELECTRIC THROTTLE CONTROL ACTUATOR VISUALLY
1. Turn ignition switch OFF.
2. Remove the intake air duct.
3. Check if foreign matter is caught between the throttle valve and the housing.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Remove the foreign matter and clean the electric throttle control actuator inside, then perform
throttle valve closed position learning. Refer to EC-147, "
Work Procedure".
2.REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
Replace electric throttle control actuator. Refer to EM-30, "
Removal and Installation".
>> INSPECTION END
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P1225 CTP LEARNING-B1
(Closed throttle position
learning performance) Closed throttle position learning value is
excessively low.
 Electric throttle control actuator
(TP sensor 1 and 2)
Revision: 2010 May2011 QX56

P1226 TP SENSOREC-407
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P1226 TP SENSOR
DTC LogicINFOID:0000000006217917
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 10 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Repeat steps 2 and 3 for 32 times.
5. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-407, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217918
1.CHECK ELECTRIC THROTTLE CONTROL ACTUATOR VISUALLY
1. Turn ignition switch OFF.
2. Remove the intake air duct.
3. Check if foreign matter is caught between the throttle valve and the housing.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Remove the foreign matter and clean the electric throttle control actuator inside, then perform
throttle valve closed position learning. Refer to EC-147, "
Work Procedure".
2.REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
Replace electric throttle control actuator. Refer to EM-30, "
Removal and Installation".
>> INSPECTION END
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P1226 CTP LEARNING-B1
(Closed throttle position
learning performance) Closed throttle position learning is not per-
formed successfully, repeatedly.
 Electric throttle control actuator
(TP sensor 1 and 2)
Revision: 2010 May2011 QX56