fuel INFINITI FX35 2008 Manual Online

EC-74
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ON BOARD DIAGNOSTIC (OBD) SYSTEM
tified codes can be identified by using the CONSULT-II
I or GST. A DTC will be used as an example for how to
read a code.
A particular trouble code can be identified by the number of four-digit numeral flashes. The “zero” is indicated
by the number of ten flashes. The “A” is indicated by the number of eleven flash. The length of time the
1,000th-digit numeral flashes on and off is 1.2 seconds consisting of an ON (0.6-second) - OFF (0.6-second)
cycle.
The 100th-digit numeral and lower digit numerals cons ist of a 0.3-second ON and 0.3-second OFF cycle.
A change from one digit numeral to another occurs at an inte rval of 1.0-second OFF. In other words, the later
numeral appears on the display 1.3 seconds after the former numeral has disappeared.
A change from one trouble code to another occu rs at an interval of 1.8-second OFF.
In this way, all the detected malfunctions are classi fied by their DTC numbers. The DTC 0000 refers to no mal-
function. (See EC-17
)
How to Erase Diagnostic Test Mode II (Self-diagnostic Results)
The DTC can be erased from the back up memory in t he ECM by depressing accelerator pedal. Refer to "How
to Set Diagnostic Test Mode II (Self-diagnostic Results)".
 If the battery is disconnected, the DTC will be lost from the backup memory within 24 hours.
 Be careful not to erase the stored memo ry before starting trouble diagnoses.
OBD System Operation ChartINFOID:0000000001325918
RELATIONSHIP BETWEEN MIL, 1ST TRIP DTC, DTC, AND DETECTABLE ITEMS
 When a malfunction is detected for the 1st time, the 1st trip DTC and the 1st trip freeze frame data are
stored in the ECM memory.
 When the same malfunction is detected in two consec utive trips, the DTC and the freeze frame data are
stored in the ECM memory, and the MIL will come on. For details, refer to EC-54, "
Two Trip Detection Logic".
 The MIL will go off after the vehicle is driven 3 time s (drive pattern B) with no malfunction. The drive is
counted only when the recorded driving pattern is met (as stored in the ECM). If another malfunction occurs
while counting, the counter will reset.
 The DTC and the freeze frame data will be stored until the vehicle is driven 40 times (driving pattern A) with-
out the same malfunction recurring (except for Misfire and Fuel Injection System). For Misfire and Fuel Injec-
tion System, the DTC and freez e frame data will be stored until the vehicle is driven 80 times (driving pattern
PBIB3005E
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ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-75
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C) without the same malfunction recurring. The “TIM
E” in “SELF-DIAGNOSTIC RESULTS” mode of CON-
SULT-III will count the number of times the vehicle is driven.
 The 1st trip DTC is not displayed when the se lf-diagnosis results in OK for the 2nd trip.
SUMMARY CHART
For details about patterns B and C under “Fuel Injection System ” and “Misfire”, see "EXPLANATION FOR DRIVING PATTERNS FOR
“MISFIRE ”, “FUEL INJECTION SYSTEM”".
For details about patterns A and B under Other, see "EXPLANATION FOR DRIVING PATTERNS FOR “MISFIRE DETERIORATION>”, “FUEL INJECTION SYSTEM”".
*1: Clear timing is at the moment OK is detected.
*2: Clear timing is when the same malfunction is detected in the 2nd trip.
RELATIONSHIP BETWEEN MIL, DTC, 1ST TRIP DTC AND DRIVING PATTERNS FOR “MISFIRE ”
, “FUEL INJECTION SYSTEM”
Items Fuel Injection System Misfire Other
MIL (goes off) 3 (pattern B) 3 (pattern B) 3 (pattern B)
DTC, Freeze Frame Data (no
display) 80 (pattern C) 80 (pa
ttern C) 40 (pattern A)
1st Trip DTC (clear) 1 (pattern C), *
11 (pattern C), *11 (pattern B)
1st Trip Freeze Frame Data
(clear) *1, *2 *1, *2 1 (pattern B)
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EC-76
< SERVICE INFORMATION >[VQ35DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
EXPLANATION FOR DRIVING PATTERNS FOR “M
ISFIRE TION>”, “FUEL INJECTION SYSTEM”

Driving pattern B means the vehicle operation as follows:
*1: When the same malfunction is de-
tected in two consecutive trips, MIL
will light up. *2: MIL will go off after vehicle is driven 3
times (pattern B) without any mal-
functions. *3: When the same malfunction is de-
tected in two consecutive trips, the
DTC and the freeze frame data will be
stored in ECM.
*4: The DTC and the freeze frame data will not be displayed any longer after
vehicle is driven 80 times (pattern C)
without the same malfunction. (The
DTC and the freeze frame data still
remain in ECM.) *5: When a malfunction is detected for
the 1st time, the 1st trip DTC and the
1st trip freeze frame data will be
stored in ECM. *6: The 1st trip DTC and the 1st trip
freeze frame data will be cleared at
the moment OK is detected.
*7: When the same malfunction is de- tected in the 2nd trip, the 1st trip
freeze frame data will be cleared. *8: 1st trip DTC will
be cleared when ve-
hicle is driven once (pattern C) with-
out the same malfunction after DTC
is stored in ECM.
SEF392S
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ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-77
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All components and systems should be monitored at least once by the OBD system.
 The B counter will be cleared when the malfunction is
detected once regardless of the driving pattern.
 The B counter will be counted up when driving pattern B is satisfied without any malfunction.
 The MIL will go off when the B counter reaches 3. (*2 in “OBD SYSTEM OPERATION CHART”)

Driving pattern C means the vehicle operation as follows:
The following conditions should be satisfied at the same time:
Engine speed: (Engine speed in the freeze frame data) ±375 rpm
Calculated load value: (Calculated load value in the freeze frame data) x (1 ±0.1) [%]
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).
Example:
If the stored freeze frame data is as follows:
Engine speed: 850 rpm, Calculated load val ue: 30%, Engine coolant temperature: 80°C (176 °F)
To be satisfied with driving pattern C, the v ehicle should run under the following conditions:
Engine speed: 475 - 1,225 rpm, Calculated load value: 27 - 33%, Engine coolant temperature: more than 70°C
(158 °F)
 The C counter will be cleared when the malfunction is detected regardless of vehicle conditions above.
 The C counter will be counted up when vehicle conditions above is satisfied without the same malfunction.
 The DTC will not be displayed after C counter reaches 80.
 The 1st trip DTC will be cleared when C counter is counted once without the same malfunction after DTC is
stored in ECM.
RELATIONSHIP BETWEEN MIL, DTC, 1ST TRIP DTC AND DRIVING PATTERNS EXCEPT FOR
“MISFIRE ”, “FUEL INJECTION SYSTEM”
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EC-78
< SERVICE INFORMATION >[VQ35DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
EXPLANATION FOR DRIVING PATTERNS EXCEPT FOR “MISFIRE RIORATION>”, “FUEL INJECTION SYSTEM”
*1: When the same malfunction is de-
tected in two consecutive trips, MIL
will light up. *2: MIL will go off after vehicle is driven 3
times (pattern B) without any mal-
functions. *3: When the same malfunction is de-
tected in two consecutive trips, the
DTC and the freeze frame data will be
stored in ECM.
*4: The DTC and the freeze frame data will not be displayed any longer after
vehicle is driven 40 times (pattern A)
without the same malfunction.
(The DTC and the freeze frame data
still remain in ECM.) *5: When a malfunction is detected for
the 1st time, the 1st trip DTC and the
1st trip freeze frame data will be
stored in ECM. *6: 1st trip DTC will
be cleared after vehi-
cle is driven once (pattern B) without
the same malfunction.
*7: When the same malfunction is de- tected in the 2nd trip, the 1st trip
freeze frame data will be cleared.
SEF393SD
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BASIC SERVICE PROCEDUREEC-87
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1.
Check that throttle valve is fully closed.
2. Check PCV valve operation.
3. Check that downstream of throttl e valve is free from air leakage.
4. When the above three items check out OK, engine component parts and their installation condi-
tion are questionable. Check and el iminate the cause of the incident.
It is useful to perform EC-131
.
5. If any of the following conditi ons occur after the engine has started, eliminate the cause of the
incident and perform Idle Air Vo lume Learning all over again:
 Engine stalls.
 Erroneous idle.
Fuel Pressure CheckINFOID:0000000001325926
FUEL PRESSURE RELEASE
With CONSULT-III
1. Turn ignition switch ON.
2. Perform “FUEL PRESSURE RELEASE” in “WORK SUPPORT” mode with CONSULT-III.
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel pressure.
5. Turn ignition switch OFF.
Without CONSULT-III
1. Remove fuel pump fuse located in IPDM E/R.
2. Start engine.
3. After engine stalls, crank it two or three times to release all fuel pressure.
4. Turn ignition switch OFF.
5. Reinstall fuel pump fuse after servicing fuel system.
FUEL PRESSURE CHECK
CAUTION:
Before disconnecting fuel line, release fuel pressure from fuel line to eliminate danger.
NOTE:
 Prepare pans or saucers under the disconnected fuel line because the fuel may spill out. The fuel
pressure cannot be completely released because S50 models do not have fuel return system.
 Use Fuel Pressure Gauge Kit (J-44321) to check fuel pressure.
1. Release fuel pressure to zero. Refer to “FUEL PRESSURE RELEASE”.
2. Install the inline fuel quick disconnected fitting between fuel damper and fuel injector tube.
3. Connect the fuel pressure test gauge (quick connector adapter hose) to the inline fuel quick disconnected fitting.
4. Turn ignition switch ON and check for fuel leakage.
5. Start engine and check for fuel leakage.
6. Read the indication of fuel pressure gauge.
7. If result is unsatisfactory, go to next step.
8. Check the following.  Fuel hoses and fuel tubes for clogging
 Fuel filter for clogging
PBIB1603E
At idling: Approximately 350 kPa (3.57 kg/cm2, 51 psi)PBIB1571E
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EC-88
< SERVICE INFORMATION >[VQ35DE]
BASIC SERVICE PROCEDURE
 Fuel pump
 Fuel pressure regulator for clogging
If OK, replace fuel pressure regulator.
If NG, repair or replace.
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TROUBLE DIAGNOSISEC-89
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TROUBLE DIAGNOSIS
Trouble Diagnosis IntroductionINFOID:0000000001325927
INTRODUCTION
The engine has an ECM to control major systems such as fuel con-
trol, ignition control, idle air c
ontrol system, etc. The ECM accepts
input signals from sensors and instantly drives actuators. It is essen-
tial that both input and output si gnals are proper and stable. At the
same time, it is important that there are no malfunctions such as vac-
uum leaks, fouled spark plugs, or other malfunctions with the engine.
It is much more difficult to diagnose an incident that occurs intermit-
tently rather than continuously. Most intermittent incidents are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.
A visual check only may not find t he cause of the incidents. A road
test with CONSULT-III (or GST) or a circuit tester connected should
be performed. Follow the WORK FLOW on “WORK FLOW”.
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such incidents, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A DIAGNOSTIC WORKSHEET like the
example on “DIAGNOSTIC WORKSHEET” should be used.
Start your diagnosis by looking for conventional malfunctions first.
This will help troubleshoot driveability malfunctions on an electroni-
cally controlled engine vehicle.
WORK FLOW
MEF036D
SEF233G
SEF234G
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TROUBLE DIAGNOSISEC-91
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2.CHECK DTC*1
1. Check DTC*1.
2. Perform the following procedure if DTC*
1 is displayed.
- Record DTC*
1 and freeze frame data*2. (Print them out with CONSULT-III or GST.)
- Erase DTC*
1. (Refer to EC-55, "Emission-Related Diagnostic Information".)
- Study the relationship between the cause detected by DTC*
1 and the symptom described by the cus-
tomer. (Symptom Matrix Chart is useful. Refer to EC-96, "
Symptom Matrix Chart".)
3. Check related service bulletins for information.
Is any symptom described and any DTC detected?
Symptom is described, DTC*1 is displayed>>GO TO 3.
Symptom is described, DTC*
1 is not displayed>>GO TO 4.
Symptom is not described, DTC*
1 is displayed>>GO TO 5.
3.CONFIRM THE SYMPTOM
Try to confirm the symptom described by the customer (except MIL ON).
DIAGNOSIS WORK SHEET is usef ul to verify the incident.
Connect CONSULT-III to the vehicle and check diagnosis results.
Verify relation between the symptom and t he condition when the symptom is detected.
>> GO TO 5.
4.CONFIRM THE SYMPTOM
Try to confirm the symptom described by the customer.
DIAGNOSIS WORK SHEET is usef ul to verify the incident.
Connect CONSULT-III to the vehicle and check diagnosis results.
Verify relation between the symptom and t he condition when the symptom is detected.
>> GO TO 6.
5.PERFORM DTC CONFIRMATION PROCEDURE
Perform DTC Confirmation Procedure for the displayed DTC*
1, and then make sure that DTC*1 is detected
again.
If two or more DTCs*
1 are detected, refer to EC-93, "DTC Inspection Priority Chart" and determine trouble
diagnosis order.
NOTE:
 Freeze frame data*
2 is useful if the DTC*1 is not detected.
 Perform Overall Function Check if DTC Confirma tion Procedure is not included on Service Manual. This
simplified check procedure is an effective alternative though DTC*
1 cannot be detected during this check.
If the result of Overall Function Check is NG, it is the same as the detection of DTC*
1 by DTC Confirmation
Procedure.
Is DTC*
1 detected?
Yes >> GO TO 10.
No >> Check according to EC-139
.
6.PERFORM BASIC INSPECTION
Perform EC-80, "
Basic Inspection"
With CONSULT-III>>GO TO 7.
Without CONSULT-III>>GO TO 9.
7.PERFORM SPEC IN DATA MONITOR MODE
With CONSULT-III
Make sure that “MAS A/F SE-B1”, “B/FUEL SCHDL”, and “A/F ALPHA-B1”, “A/F ALPHA-B2” are within the SP
value using CONSULT-III “SPEC” in “DATA MONITOR” mode. Refer to EC-131, "
Diagnosis Procedure".
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TROUBLE DIAGNOSISEC-93
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There are many operating conditions that lead to the malfunction of
engine components. A good grasp of such conditions can make trou-
bleshooting faster and more accurate.
In general, each customer feels differently about a incident. It is
important to fully understand the symptoms or conditions for a cus-
tomer complaint.
Utilize a diagnostic worksheet like the one on the next page in order
to organize all the information for troubleshooting.
Some conditions may cause the MI
L to come on steady or blink and
DTC to be detected. Examples:
 Vehicle ran out of fuel, which caused the engine to misfire.
 Fuel filler cap was left off or incorrectly screwed on, allowing fuel to evaporate into the atmosphere.
Worksheet Sample
DTC Inspection Priority ChartINFOID:0000000001325928
If some DTCs are displayed at the same time, per form inspections one by one based on the following priority
chart.
NOTE:
SEF907L
MTBL0017
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