service INFINITI QX56 2009 Factory Service Manual
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![INFINITI QX56 2009 Factory Service Manual
EC-66
< FUNCTION DIAGNOSIS >[VK56DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
*: This function is not necessary in the usual service procedure.
SELF-DIAG RESULTS MODE
Self Diagnostic Item
Regarding items of INFINITI QX56 2009 Factory Service Manual
EC-66
< FUNCTION DIAGNOSIS >[VK56DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
*: This function is not necessary in the usual service procedure.
SELF-DIAG RESULTS MODE
Self Diagnostic Item
Regarding items of](/img/42/57031/w960_57031-1392.png)
EC-66
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ON BOARD DIAGNOSTIC (OBD) SYSTEM
*: This function is not necessary in the usual service procedure.
SELF-DIAG RESULTS MODE
Self Diagnostic Item
Regarding items of DTC and 1st trip DTC, refer to
EC-456, "DTC Index".
Freeze Frame Data and 1st Trip Freeze Frame Data
EVAP SYSTEM CLOSE CLOSE THE EVAP CANISTER VENT CONTROL VALVE IN
ORDER TO MAKE EVAP SYSTEM CLOSE UNDER THE
FOLLOWING CONDITIONS.
IGN SW ON
ENGINE NOT RUNNING
AMBIENT TEMPERATURE IS ABOVE 0 °C (32 °F).
NO VACUUM AND NO HIGH PRESSURE IN EVAP SYS- TEM
FUEL TANK TEMP. IS MORE THAN 0 °C (32 °F).
WITHIN 10 MINUTES AFTER STARTING “EVAP SYS- TEM CLOSE”
WHEN TRYING TO EXECUTE “EVAP SYSTEM CLOSE” UNDER THE CONDITION EXCEPT ABOVE, CONSULT-
III WILL DISCONTINUE IT AND DISPLAY APPROPRI-
ATE INSTRUCTION.
NOTE:
WHEN STARTING ENGINE, CONSULT-III MAY DIS-
PLAY “BATTERY VOLTAGE IS LOW. CHARGE BAT-
TERY”, EVEN IN USING CHARGED BATTERY. When detecting EVAP vapor leak
point of EVAP system
VIN REGISTRATION IN THIS MODE, VIN IS REGI STERED IN ECM When registering VIN in ECM
TARGET IDLE RPM ADJ* IDLE CONDITION When setting target idle speed
TARGET IGN TIM ADJ* IDLE CONDITION Wh en adjusting target ignition tim-
ing
WORK ITEM CONDITION USAGE
Freeze frame data
item* Description
DIAG TROUBLE
CODE
[PXXXX] The engine control co
mponent part/control system has a trouble code, it is displayed as PXXXX. (Refer to
EC-456, "DTC Index"
.)
FUEL SYS-B1 “Fuel injection system status” at the moment a malfunction is detected is displayed.
One mode in the following is displayed. Mode2: Open loop due to detected system malfunction
Mode3: Open loop due to driving conditions (power enrichment, deceleration enleanment)
Mode4: Closed loop - using oxygen sensor(s) as feedback for fuel control
Mode5: Open loop - has not yet satisfied condition to go to closed loop
FUEL SYS-B2
CAL/LD VALUE [%] The calculated load value at the moment a malfunction is detected is displayed.
COOLANT TEMP
[
° C] or [ °F] The engine coolant temperature at the moment a malfunction is detected is displayed.
L-FUEL TRM-B1 [%] “Long-term fuel trim” at the moment a malfunction is detected is displayed. The long-term fuel trim indicates much more gradual feedback compensation to the base fuel schedule than short-term fuel trim.
L-FUEL TRM-B2 [%]
S-FUEL TRM-B1 [%] “Short-term fuel trim” at the moment a malfunction is detected is displayed.
The short-term fuel trim indicates dynamic or instantaneous feedback compensation to the base fuel sched-
ule.
S-FUEL TRM-B2 [%]
ENGINE SPEED [rpm] The engine speed at the moment a malfunction is detected is displayed.
VEHICL SPEED
[km/h] or [mph] The vehicle speed at the moment a malfunction is detected is displayed.
ABSOL TH-P/S
[%] The throttle valve opening at the moment a malfunction is detected is displayed.
B/FUEL SCHDL
[msec] The base fuel schedule at the moment a malfunction is detected is displayed.
Revision: December 20092009 QX56
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EC-72
< FUNCTION DIAGNOSIS >[VK56DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
*: DTC P1442 and P1456 does not apply to JA60 models but appears in DTC Work Support Mode screens.
Generic Scan Tool (GST) Functi INFINITI QX56 2009 Factory Service Manual
EC-72
< FUNCTION DIAGNOSIS >[VK56DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
*: DTC P1442 and P1456 does not apply to JA60 models but appears in DTC Work Support Mode screens.
Generic Scan Tool (GST) Functi](/img/42/57031/w960_57031-1398.png)
EC-72
< FUNCTION DIAGNOSIS >[VK56DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
*: DTC P1442 and P1456 does not apply to JA60 models but appears in DTC Work Support Mode screens.
Generic Scan Tool (GST) FunctionINFOID:0000000003771319
DESCRIPTION
Generic Scan Tool (OBDII scan tool) complying with SAE J1978 has
8 different functions explained below.
ISO15765-4 is used as the protocol.
The name GST or Generic Scan Tool is used in this service manual.
FUNCTION
Test mode Test item Corresponding DTC No. Reference page
EVAPORATIVE
SYSTEM PURG FLOW P0441 P0441
EC-210
EVP SML LEAK P0442/P1442*P0442
EC-215P0455EC-250
EVP V/S LEAK P0456/P1456* P0456 EC-257
PURG VOL CN/V P1444 P0443EC-222
A/F SEN1A/F SEN1 (B1) P1276 P0130
EC-136A/F SEN1 (B1) P1278/P1279 P0133EC-146
A/F SEN1 (B2) P1286 P0150EC-136
A/F SEN1 (B2) P1288/P1289 P0153EC-146
HO2S2HO2S2 (B1) P0139 P0139
EC-164
HO2S2 (B1) P1146 P0138EC-157
HO2S2 (B1) P1147 P0137EC-152
HO2S2 (B2) P0159 P0159EC-164
HO2S2 (B2) P1166 P0158EC-157
HO2S2 (B2) P1167 P0157EC-152
SEF139P
Diagnostic test mode Function
Service $01 READINESS TESTS This diagnostic service gains access to current emission-related data values, including an-
alog inputs and outputs, digital inputs and outputs, and system status information.
Service $02 (FREEZE DATA) This diagnostic service gains access to emission-related data value which were stored by
ECM during the freeze frame. For details, refer to
EC-456, "DTC Index"
.
Service $03 DTCs This diagnostic service gains access to emission-related power train trouble codes which
were stored by ECM.
Service $04 CLEAR DIAG INFO This diagnostic service can clear all emission-related diagnostic information. This in-
cludes:
Clear number of diagnostic trouble codes (Service $01)
Clear diagnostic trouble codes (Service $03)
Clear trouble code for freeze frame data (Service $01)
Clear freeze frame data (Service $02)
Reset status of system monitoring test (Service $01)
Clear on board monitoring test results (Service $06 and $07)
Service $06 (ON BOARD TESTS) This diagnostic service accesses the results of on board diagnostic monitoring tests of
specific components/systems that are not continuously monitored.
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ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-73
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INSPECTION PROCEDURE
1. Turn ignition switch OFF.
2. Connect GST to data link connector, which is INFINITI QX56 2009 Factory Service Manual
ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-73
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INSPECTION PROCEDURE
1. Turn ignition switch OFF.
2. Connect GST to data link connector, which is](/img/42/57031/w960_57031-1399.png)
ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-73
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INSPECTION PROCEDURE
1. Turn ignition switch OFF.
2. Connect GST to data link connector, which is located under LH
dash panel near the hood opener handle.
3. Turn ignition switch ON.
4. Enter the program according to instruction on the screen or in the operation manual.
(*: Regarding GST screens in this section, sample screens are
shown.)
5. Perform each diagnostic service according to each service pro- cedure.
For further information, see th e GST Operation Manual of
the tool maker.
Service $07 (ON BOARD TESTS) This diagnostic service enables the off board test drive to obtain test results for emission-
related powertrain components/systems that are continuously monitored during normal
driving conditions.
Service $08 — This diagnostic service can close EVAP system in ignition switch ON position (Engine
stopped). When this diagnostic service is performed, the EVAP canister vent control valve
can be closed.
In the following conditions, this diagnostic service cannot function.
Low ambient temperature
Low battery voltage
Engine running
Ignition switch OFF
Low fuel temperature
Too much pressure is applied to EVAP system
Service $09 (CALIBRATION ID) This diagnostic service enables the off-board test device to request specific vehicle infor-
mation such as Vehicle Identification Number (VIN) and Calibration IDs.
Diagnostic test mode Function
BBIA0369E
SEF398S
SEF416S
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P0011, P0021 IVT CONTROLEC-91
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Harness for open or short between intake valve timing control solenoid valve and IPDM E/R.
>> Repair o INFINITI QX56 2009 Factory Service Manual
P0011, P0021 IVT CONTROLEC-91
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Harness for open or short between intake valve timing control solenoid valve and IPDM E/R.
>> Repair o](/img/42/57031/w960_57031-1417.png)
P0011, P0021 IVT CONTROLEC-91
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Harness for open or short between intake valve timing control solenoid valve and IPDM E/R.
>> Repair open circuit or short to ground or short to power in harness or connectors.
11 .CHECK INTAKE VALVE TIMING CONTROL SOLENO ID VALVE OUTPUT SIGNAL CIRCUIT FOR OPEN
AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between the following; ECM terminal 10 and intake valve timing control solenoid valve (Bank 1) terminal 1 or
ECM terminal 11 and intake valve timing control solenoid valve (Bank 2) terminal 1.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 12.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
12.CHECK INTAKE VALVE TIMING CONTROL SOLENOID VALVE
Refer to EC-92, "Component Inspection"
.
OK or NG
OK >> GO TO 13.
NG >> Replace malfunctioning intake valve timing control solenoid valve. Refer to EC-492
.
13.CHECK CRANKSHAFT POSITION SENSOR (POS)
Refer to EC-200, "Component Inspection"
.
OK or NG
OK >> GO TO 14.
NG >> Replace crankshaft position sensor (POS).
14.CHECK CAMSHAFT POSIT ION SENSOR (PHASE)
Refer to EC-204, "Component Inspection"
.
OK or NG
OK >> GO TO 15.
NG >> Replace malfunctioning camshaft position sensor (PHASE). Refer to EC-493
.
15.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 16.
NG >> Remove debris and clean the signal pick-up cutout of camshaft sprocket.
16.CHECK TIMING CHAIN INSTALLATION
Check service records for any recent repairs that may cause timing chain misaligned.
Are there any service records that may cause timing chain misaligned?
Ye s o r N o
Yes >> Check timing chain installation. Refer to EM-45, "Removal and Installation".
No >> GO TO 17.
17.CHECK LUBRICATION CIRCUIT
Refer to EM-62, "Inspection after Installation"
.
OK or NG
OK >> GO TO 18.
NG >> Clean lubrication line. Continuity should exist.
Revision: December 20092009 QX56
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EC-104
< COMPONENT DIAGNOSIS >[VK56DE]
P0101 MAF SENSOR
1. Start engine and warm it up to normal operating temperature.
If engine cannot be started, go to EC-105, "Diagnosis Procedure"
.
2. Select INFINITI QX56 2009 Factory Service Manual
EC-104
< COMPONENT DIAGNOSIS >[VK56DE]
P0101 MAF SENSOR
1. Start engine and warm it up to normal operating temperature.
If engine cannot be started, go to EC-105, "Diagnosis Procedure"
.
2. Select](/img/42/57031/w960_57031-1430.png)
EC-104
< COMPONENT DIAGNOSIS >[VK56DE]
P0101 MAF SENSOR
1. Start engine and warm it up to normal operating temperature.
If engine cannot be started, go to EC-105, "Diagnosis Procedure"
.
2. Select “DATA MONITOR” mode with CONSULT-III.
3. Check the voltage of “MAS A/F SE-B1” with “DATA MONITOR”.
4. Increases engine speed to about 4,000 rpm.
5. Monitor the linear voltage rise in response to engine speed
increases.
If NG, go to EC-105, "Diagnosis Procedure"
.
If OK, go to following step.
6. Maintain the following conditions for at least 10 consecutive seconds.
7. Check 1st trip DTC.
8. If 1st trip DTC is detected, go to EC-105, "Diagnosis Procedure"
.
Overall Function CheckINFOID:0000000003771356
PROCEDURE FOR MALFUNCTION B
Use this procedure to check the overall function of the mass air flow sensor circuit. During this check, a 1st trip
DTC might not be confirmed.
With GST
1. Start engine and warm it up to normal operating temperature.
2. Select Service $01 with GST.
3. Check the mass air flow sensor signal with Service $01.
4. Check for linear mass air flow sensor signal value rise in response to increases to about 4,000 rpm in engine speed.
5. If NG, go to EC-105, "Diagnosis Procedure"
.
PBIB3457E
ENG SPEED More than 2,000 rpm
TP SEN 1-B1 More than 3V
TP SEN 2-B1 More than 3V
Selector lever Suitable position
Driving location Driving vehicle uphill (Increased engine load) will help
maintain the driving conditions required for this test.
SEF534P
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P0133, P0153 A/F SENSOR 1EC-147
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1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait a INFINITI QX56 2009 Factory Service Manual
P0133, P0153 A/F SENSOR 1EC-147
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1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait a](/img/42/57031/w960_57031-1473.png)
P0133, P0153 A/F SENSOR 1EC-147
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1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1minute under no load.
4. Let engine idle for 1 minute.
5. Select “A/F SEN1(B1) P1278/P1279”
(for DTC P0133) or “A/F SEN1(B2) P1288/P1289” (for DTC P0153)
of “A/F SEN1” in “DTC WORK SUPPORT” mode with CONSULT-III.
6. Touch “START”. If “COMPLETED” appears on CONSULT-III screen, go to step 10.
If “COMPLETED” does not appear on CONSULT- III screen, go to the following step.
7. After perform the following procedure, “TESTIN G” will be displayed on the CONSULT-III screen.
a. Increase the engine speed up to 4,000 to 5,000 rpm and keep it for 10 seconds.
b. Fully release accelerator pedal and then let engine idle for about 10 seconds. If “TESTING” is not displayed after 10 seconds, refer to EC-74
.
8. Wait for about 20 seconds at idle under the conditi on that “TESTING” is displayed on the CONSULT-III
screen.
9. Make sure that “TESTING” changes to “COMPLETED”. If “TESTING” changed to “OUT OF CONDITION”, refer to EC-74
.
10. Make sure that “OK” is display ed after touching “SELF-DIAG RESULT”.
If “NG” is displayed, go to EC-147, "Diagnosis Procedure"
.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Select Service $01 with GST.
3. Calculate the total value of “Short term f uel trim” and “Long term fuel trim” indications.
Make sure that the total percentage should be within ±15%.
If OK, go to the following step.
If NG, check the following.
Intake air leaks
Exhaust gas leaks
Incorrect fuel pressure
Lack of fuel
Fuel injector
Incorrect PCV hose connection
PCV valve
Mass air flow sensor
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1minute under no load.
6. Let engine idle for 1 minute.
7. Increase the engine speed up to 4,000 to 5,000 rpm and keep it for 10 seconds.
8. Fully release accelerator pedal and then let engine idle for about 1 minute.
9. Select Service $07 with GST. If the 1st trip DTC is displayed, go to EC-147, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771414
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
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EC-170
< COMPONENT DIAGNOSIS >[VK56DE]
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
7. If it is difficult to start engine at step 6,
the fuel injection system has a malfunction, too.
8. Crank engine INFINITI QX56 2009 Factory Service Manual
EC-170
< COMPONENT DIAGNOSIS >[VK56DE]
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
7. If it is difficult to start engine at step 6,
the fuel injection system has a malfunction, too.
8. Crank engine](/img/42/57031/w960_57031-1496.png)
EC-170
< COMPONENT DIAGNOSIS >[VK56DE]
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
7. If it is difficult to start engine at step 6,
the fuel injection system has a malfunction, too.
8. Crank engine while depressing accelerator pedal. If engine starts, go to EC-170, "Diagnosis Procedure"
. If
engine does not start, check exhaust and intake air leak visually.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Disconnect mass air flow sensor harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con- nector.
6. Select Service $03 with GST. Make sure DTC P0102 is detected.
7. Select Service $04 with GST and erase the DTC P0102.
8. Start engine again and let it idle for at least 10 minutes.
9. Select Service $07 with GST. The 1st trip DTC P0171 or P0174 should be detected at this stage, if a malfunction exists. If so, go
to EC-170, "Diagnosis Procedure"
.
NOTE:
If 1st trip DTC is not detected during above proc edure, performing the following procedure is advised.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Start engine and drive the vehicle under the similar conditions to (1st trip) Freeze Frame Data for 10 min- utes. Refer to the table below.
Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Da ta means the vehicle operation that the following con-
ditions should be satisfied at the same time.
10. If it is difficult to start engine at step 8, the fuel injection system has a malfunction.
11. Crank engine while depressing accelerator pedal. If engine starts, go to EC-170, "Diagnosis Procedure"
.
If engine does not start, check exhaus t and intake air leak visually.
Diagnosis ProcedureINFOID:0000000003771435
1.CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
Engine coolant temperature (T)
condition When the freeze frame data shows lower than 70
°C (158 °F),
T should be lower than 70 °C (158 °F).
When the freeze frame data shows higher than or equal to 70 °C (158 °F),
T should be higher than or equal to 70 °C (158 °F).
BBIA0368E
Engine speed Engine speed in the freeze frame data ± 400 rpm
Vehicle speed Vehicle speed in the freeze frame data ± 10 km/h (6 MPH)
Engine coolant temperature (T)
condition When the freeze frame data shows lower than 70
°C (158 °F),
T should be lower than 70 °C (158 °F).
When the freeze frame data shows higher than or equal to 70 °C (158 °F),
T should be higher than or equal to 70 °C (158 °F).
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EC-172
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P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
6. Also check harness for short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or sh INFINITI QX56 2009 Factory Service Manual
EC-172
< COMPONENT DIAGNOSIS >[VK56DE]
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
6. Also check harness for short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or sh](/img/42/57031/w960_57031-1498.png)
EC-172
< COMPONENT DIAGNOSIS >[VK56DE]
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
6. Also check harness for 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 FUEL PRESSURE
1. Release fuel pressure to zero. Refer to EC-487, "Fuel Pressure Check"
.
2. Install fuel pressure gauge kit [SST (J -44321)] and check fuel pressure. Refer to EC-487, "Fuel Pressure
Check".
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
Fuel pump and circuit (Refer to EC-395, "Diagnosis Procedure"
.)
Fuel pressure regulator (Refer to EC-487, "Fuel Pressure Check"
.)
Fuel lines
Fuel filter for clogging
>> Repair or replace.
6.CHECK MASS AIR FLOW SENSOR
With CONSULT-III
1. Install all removed parts.
2. Check “MASS AIR FLOW” in “DATA MONITOR” mode with CONSULT-III.
With GST
1. Install all removed parts.
2. Check mass air flow sensor signal in Service $01 with GST.
OK or NG
OK >> GO TO 7.
NG >> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or
grounds. Refer to EC-103
.
7.CHECK FUNCTION OF FUEL INJECTOR
With CONSULT-III
1. Start engine.
2. Perform “POWER BALANCE” in “A CTIVE TEST” mode with CONSULT-III.
3. Make sure that each circuit produces a momentary engine speed drop.
Without CONSULT-III
1. Start engine. At idling: Approximately 350 kPa (3.57 kg/cm
2, 51 psi)
3.0 - 9.0 g·m/sec: at idling
9.0 - 28.0 g·m/sec: at 2,500 rpm
3.0 - 9.0 g·m/sec: at idling
9.0 - 28.0 g·m/sec: at 2,500 rpm
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P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-175
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P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
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the fuel injection system has a ma](/img/42/57031/w960_57031-1501.png)
P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-175
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the fuel injection system has a malfunction, too.
8. Crank engine while depressing accelerator pedal. If engine starts, go to EC-175, "Diagnosis Procedure"
. If engine does not start, remove spark plugs and
check for fouling, etc.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Disconnect mass air flow sensor harness connector. Then restart and run engine for at least 5 seconds at idle speed.
4. Stop engine and reconnect mass air flow sensor harness con- nector.
5. Select Service $03 with GST. Make sure DTC P0102 is detected.
6. Select Service $04 with GST and erase the DTC P0102.
7. Start engine again and let it idle for at least 10 minutes.
8. Select Service $07 with GST. The 1st trip DTC P0172 or P0175 should be detected at this stage, if a malfunction exists. If so, go
to EC-175, "Diagnosis Procedure"
.
NOTE:
If 1st trip DTC is not detected during above proc edure, performing the following procedure is advised.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Start engine and drive the vehicle under the similar condi tions to (1st trip) Freeze Frame Data for 10 min-
utes. Refer to the table below.
Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Da ta means the vehicle operation that the following con-
ditions should be satisfied at the same time.
9. If it is difficult to start engine at step 7, the fuel injection system has a malfunction.
10. Crank engine while depressing accelerator pedal. If engine starts, go to EC-175, "Diagnosis Procedure"
. If engine does not start, remove spark plugs and
check for fouling, etc.
Diagnosis ProcedureINFOID:0000000003771438
1.CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
Engine coolant temperature (T)
condition When the freeze frame data shows lower than 70
°C (158 °F),
T should be lower than 70 °C (158 °F).
When the freeze frame data shows higher than or equal to 70 °C (158 °F),
T should be higher than or equal to 70 °C (158 °F).
BBIA0368E
Engine speed Engine speed in the freeze frame data ± 400 rpm
Vehicle speed Vehicle speed in the freeze frame data ± 10 km/h (6 MPH)
Engine coolant temperature (T)
condition When the freeze frame data shows lower than 70
°C (158 °F),
T should be lower than 70 °C (158 °F).
When the freeze frame data shows higher than or equal to 70 °C (158 °F),
T should be higher than or equal to 70 °C (158 °F).
Revision: December 20092009 QX56
Page 1504 of 4171
![INFINITI QX56 2009 Factory Service Manual
P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-177
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to po INFINITI QX56 2009 Factory Service Manual
P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-177
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to po](/img/42/57031/w960_57031-1503.png)
P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-177
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
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 FUEL PRESSURE
1. Release fuel pressure to zero. Refer to EC-487, "Fuel Pressure Check"
.
2. Install fuel pressure gauge and check fuel pressure. Refer to EC-487, "Fuel Pressure Check"
.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
Fuel pump and circuit (Refer to EC-395, "Diagnosis Procedure"
.)
Fuel pressure regulator (Refer to EC-487, "Fuel Pressure Check"
.)
>> Repair or replace.
6.CHECK MASS AIR FLOW SENSOR
With CONSULT-III
1. Install all removed parts.
2. Check “MASS AIR FLOW” in “DATA MONITOR” mode with CONSULT-III.
With GST
1. Install all removed parts.
2. Check mass air flow sensor signal in Service $01 with GST.
OK or NG
OK >> GO TO 7.
NG >> Check connectors for rusted terminals or loose c onnections in the mass air flow sensor circuit or
grounds. Refer to EC-103
.
7.CHECK FUNCTION OF FUEL INJECTOR
With CONSULT-III
1. Start engine.
2. Perform “POWER BALANCE” in “A CTIVE TEST” mode with CONSULT-III.
3. Make sure that each circuit produces a momentary engine speed drop.
Without CONSULT-III
1. Start engine. At idling: Approximately 350 kPa (3.57 kg/cm
2, 51 psi)
3.0 - 9.0 g·m/sec: at idling
9.0 - 28.0 g·m/sec: at 2,500 rpm
3.0 - 9.0 g·m/sec: at idling
9.0 - 28.0 g·m/sec: at 2,500 rpm
Revision: December 20092009 QX56