Fuel INFINITI QX56 2011 Factory Service Manual

EC-372
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P0550 PSP 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 PSP SENSOR GROUND 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 short to power.
Is the 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.)
PSP sensor
Connector terminal F35 1 Ground 5 V
ECM Sensor
Connector Terminal Name Connector Terminal
F 111 27Low fuel pressure sensor F25 3
Power steering pressure sensor F35 1
Cooling fan speed sensor F39 2
28 FRP sensor F26 1
+ −
Continuity
PSP sensor ECM
Connector Terminal Connector Terminal F35 3 F111 45 Existed
+ −Continuity
ECM
Connector Terminal F 111 1 0 Ground Existed
E80 174
175
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

P0850 PNP SWITCHEC-383
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P0850 PNP SWITCH
DescriptionINFOID:0000000006217884
When the selector lever position is P or N, park/neut
ral position (PNP) signal is sent to ECM from TCM.
DTC LogicINFOID:0000000006217885
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.INSPECTION START
Will CONSULT-III be used?
Will CONSULT-III be used?
YES >> GO TO 2.
NO >> GO TO 5.
2.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 3.
3.CHECK PNP SIGNAL
WITH CONSULT-III
1. Turn ignition switch ON.
2. Select “P/N POSI SW” in “DATA MONITOR” mode wit h CONSULT-III. Then check the “P/N POSI SW” sig-
nal under the following conditions.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Go to EC-384, "
Diagnosis Procedure".
4.PERFORM DTC CONFIRMATION PROCEDURE
1. Select “DATA MONITOR” mode with CONSULT-III.
2. Start engine and warm it up to normal operating temperature.
3. Maintain the following conditions for at least 50 consecutive seconds. CAUTION:
Always drive vehicle at a safe speed.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0850 P-N POS SW/CIRCUIT
(Park/neutral position
switch) The signal of the park/neutral position (PNP)
signal does not change during driving after the
engine is started.  Harness or connectors
[The park/neutral position (PNP) signal
circuit is open or shorted.]
TCM
Position (Selector lever) Known-good signal
N or P position ON
Except above position OFF
ENG SPEED 1,300 - 6,375 rpm
COOLAN TEMP/S More than 70 °C (158 °F)
B/FUEL SCHDL 2.0 - 31.8 msec
Revision: 2010 May2011 QX56

P1197 OUT OF GASEC-397
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P1197 OUT OF GAS
DescriptionINFOID:0000000006217903
This diagnosis result is detected when the fuel level
of the fuel tank is extremely low and the engine does not
run normally.
DTC LogicINFOID:0000000006217904
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-I
Start the engine.
Does the engine start?
YES >> GO TO 3.
NO >> Proceed to EC-398, "
Diagnosis Procedure".
3.PERFORM DTC CONFIRMATION PROCEDURE-II
1. Warm up the engine to the normal operating temperature. NOTE:
For best results, warm up the engine until “COOLAN TEMP/S” on “DATA MONITOR” of CONSULT-III
reaches at least 70 °C (158 °F).
2. Keep the engine speed at 3,500 rpm for 5 seconds and let it idle at least 60 seconds..
3. Check the 1st trip DTC. NOTE:
If the fuel tank has sufficient fuel, this diagnosis result may not be detected.
Is 1st trip DTC detected?
YES >> Proceed to EC-398, "Diagnosis Procedure".
NO >> INSPECTION END
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P1197 FUEL RUN OUT
(Out of gas)  Fuel rail pressure remains at 1.5 MPa (15
bar, 15.3 kg/cm
2, 217.5 psi) or less for 3
seconds or more with the fuel level too
low.
 Fuel rail pressure remains 2.7 MPa (27
bar, 27.5 kg/cm
2, 392 psi) lower than a tar-
get fuel pressure for 5 seconds or more
with the fuel level too low.
 Fuel rail pressure remains at 0.23 MPa
(2.3 bar, 2.346 kg/cm
2, 33.35 psi) or less
for 5 seconds or more with the fuel level
too low.
NOTE:
Allow engine coolant temperature to reach
70 °C (158 °F) or more once.  Out of gas
 Harness or connectors (The low pressure fuel
pump circuit is open or shorted.)
 Low pressure fuel pump
 Fuel pressure regulator
 Low pressure fuel system
 Low fuel pressure sensor
 Harness or connectors (The high pressure fuel
pump circuit is shorted.)
 High pressure fuel pump
 High pressure fuel system
 Fuel rail pressure sensor
 Disconnection of the fuel hose
Revision: 2010 May2011 QX56

EC-398
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P1197 OUT OF GAS
Diagnosis Procedure
INFOID:0000000006217905
1.REFUEL THE VEHICLE
1. Refuel 10 liter (10 US qt, 8 imp qt). CAUTION:
Never refuel more than 10 liter.
2. Start the engine and keep the engine speed at 3,000 rpm for 30 seconds. NOTE:
For best results, warm up the engine until “COOLA N TEMP/S” on “DATA MONITOR” of CONSULT-III
reaches at least 70 °C (158 °F).
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON.
5. Turn ignition switch OFF and wait at least 10 seconds.
6. Turn ignition switch ON.
7. Erase the DTC.
8. Start the engine and let it idle at least 60 seconds.
9. Perform the confirmation procedure again. Refer to EC-397, "
DTC Logic".
Is 1st trip DTC detected?
YES >> GO TO 2.
NO >> INSPECTION END
2.CHECK LOW PRESSURE FUEL PUMP
Refer to EC-512, "
Component Function Check".
Is inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace error-detected parts.
3.CHECK HIGH PRESSURE FUEL PUMP
Refer to EC-501, "
Component Function Check".
Is inspection result normal?
YES >> Check the fuel hose for disconnection and looseness.
NO >> Repair or replace error-detected parts.
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-404
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P1220 FUEL PUMP CONTROL MODULE (FPCM)
3.CHECK FPCM GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check the continuity between FPCM harness connector and ground.
3. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair open circuit or short to power in harness or connectors.
4.CHECK FPCM INPUT AND OUTPUT CIRCUITS FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check the continuity between FPCM harness connector and ECM harness connector.
3. Also check harness for short to ground and short to power.
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 FPCM and ECM
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
6.CHECK FUEL PUMP CONTROL CIRCUIT FOR OPEN AND SHORT
1. Disconnect fuel level sensor unit and fuel pump harness connector.
2. Check the continuity between FPCM harness connecto r and fuel level sensor unit and fuel pump harness
connector.
3. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 7.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
7.CHECK FPCM
Refer to EC-405, "
Component Inspection (FPCM)".
Is the inspection result normal?
YES >> GO TO 8.
NO >> Replace FPCM.
FPCM Ground Continuity
Connector Terminal
B41 5 Ground Existed
FPCM ECM Continuity
Connector Terminal Connector Terminal
B41 8
E80 125
Existed
9142
FPCM Fuel level sensor unit and fuel pump Continuity
Connector Terminal Connector Terminal
B41 6
C5 3
Existed
71
Revision: 2010 May2011 QX56

P1220 FUEL PUMP CONTROL MODULE (FPCM)
EC-405
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8.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (FPCM)INFOID:0000000006217914
1.CHECK FUEL PUMP CONTROL MODULE (FPCM)
1. Check the voltage between FPCM terminals under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace FPCM.
FPCM
Condition Voltage
Connector +
−
Te r m i n a l Te r m i n a l
B41 7 6 For 1 second after
turning ignition
switch ON Approx. 8.5 V
More than 1 seco nd after turning
ignition switch ON Approx. 0 V
Idle speed Approx. 8.5 V
Revision: 2010 May2011 QX56

EC-408
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P1421 COLD START CONTROL
P1421 COLD START CONTROL
DescriptionINFOID:0000000006288263
ECM controls ignition timing and engine idle speed when engine is started with prewarming up condition.
This control promotes the activation of three way ca
talyst by heating the catalyst and reduces emissions.
DTC LogicINFOID:0000000006288264
DTC DETECTION LOGIC
NOTE:
If DTC P1421 is displayed with other DTC, firs t perform the trouble diagnosis for other DTC.
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 more than 11 V at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-III.
4. Check the indication of “COOLAN TEMP/S”. If it is between 7 °C (45 °F) and 36 °C (97 °F), go to the following steps.
If it is below 7 °C (45 °F), warm engine up to more than 7 °C (45 °F) and retry from step 1.
If it is above 36 °C (97 °F), cool engine down to less than 36 °C (97 °F) and retry from step 1.
5. Start engine and let it idle for 5 minutes.
6. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-408, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288265
1.PERFORM IDLE AIR VOLUME LEARNING
Perform EC-148, "
Work Procedure".
Is Idle Air Volume Learning carried out successfully?
YES >> GO TO 2.
NO >> Follow the instruction of Idle Air Volume Learning.
2.CHECK INTAKE SYSTEM
Check for the cause of intake air volume lacking. Refer to the following.
 Crushed intake air passage
 Intake air passage clogging
Is the inspection result normal?
YES >> GO TO 3.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1421 Cold start emission reduction
strategy monitoring ECM does not control ignition timing and engine
idle speed properly when engine is started with
prewarming up condition.  Lack of intake air volume
 Fuel injection system
ECM
Revision: 2010 May2011 QX56

P1421 COLD START CONTROLEC-409
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NO >> Repair or replace malfunctioning part
3.CHECK FUEL INJECTION SYSTEM FUNCTION
Perform DTC Confirmation Procedure for DTC P0171, P0174. Refer to EC-263, "
DTC Logic".
Is the inspection result normal?
YES >> GO TO 4.
NO >> Go to EC-264, "
Diagnosis Procedure" for DTC P0171, P0174.
4.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Erase DTC.
3. Perform DTC Confirmation Procedure.
See EC-408, "
DTC Logic".
Is the 1st trip DTC P1421 displayed again?
YES >> GO TO 5.
NO >> INSPECTION END
5.REPLACE ECM
1. Replace ECM.
2. Go to EC-143, "
Work Procedure".
>> INSPECTION END
Revision: 2010 May2011 QX56