2007 INFINITI QX56 service

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-65
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displayed, they may be either DTCs or 1st trip DTCs. DTC No. is same as that of 1st trip DTC. These uniden-
tified codes can be identified by using the CONSULT-II 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 consist of a 0.3-second ON and 0.3-second OFF cycle.
A change from one digit numeral to another occurs at an interval 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 occurs at an interval of 1.8-second OFF.
In this way, all the detected malfunctions are classified by their DTC numbers. The DTC 0000 refers to no mal-
function. (See EC-9
)
How to Erase Diagnostic Test Mode II (Self-diagnostic Results)
The DTC can be erased from the back up memory in the ECM by depressing accelerator pedal. Refer to "How
to Erase 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 memory before starting trouble diagnoses.
OBD System Operation ChartINFOID:0000000003531608
RELATIONSHIP BETWEEN MIL, 1ST TRIP DTC, DTC, AND DETECTABLE ITEMS
• When a malfunction is detected for the first 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 consecutive 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-48, "
Two Trip Detection Logic".
• The MIL will go off after the vehicle is driven 3 times (driving 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-
PBIB3005E

EC-66
< SERVICE INFORMATION >
ON BOARD DIAGNOSTIC (OBD) SYSTEM
tion System, the DTC and freeze frame data will be stored until the vehicle is driven 80 times (driving pattern
C) without the same malfunction recurring. The “TIME” in “SELF-DIAGNOSTIC RESULTS” mode of CON-
SULT-II will count the number of times the vehicle is driven.
• The 1st trip DTC is not displayed when the self-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 ITY 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 (pattern 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)

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-67
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EXPLANATION FOR DRIVING PATTERNS FOR “MISFIRE 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 first 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

EC-68
< SERVICE INFORMATION >
ON BOARD DIAGNOSTIC (OBD) SYSTEM
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 value: 30%, Engine coolant temperature: 80°C (176°F)
To be satisfied with driving pattern C, the vehicle 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”

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-69
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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 first 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

EC-70
< SERVICE INFORMATION >
ON BOARD DIAGNOSTIC (OBD) SYSTEM

• The A counter will be cleared when the malfunction is detected regardless of (1) - (4).
• The A counter will be counted up when (1) - (4) are satisfied without the same malfunction.
• The DTC will not be displayed after the A counter reaches 40.

Driving pattern B means the vehicle operation as follows:
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 malfunctions.
• The MIL will go off when the B counter reaches 3 (*2 in OBD SYSTEM OPERATION CHART).
AEC574

BASIC SERVICE PROCEDURE
EC-71
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BASIC SERVICE PROCEDURE
Basic InspectionINFOID:0000000003531609
1.INSPECTION START
1. Check service records for any recent repairs that may indicate a related malfunction, or a current need for
scheduled maintenance.
2. Open engine hood and check the following:
- Harness connectors for improper connections
- Wiring harness for improper connections, pinches and cut
- Vacuum hoses for splits, kinks and improper connections
- Hoses and ducts for leaks
- Air cleaner clogging
- Gasket
3. Confirm that electrical or mechanical loads are not applied.
- Headlamp switch is OFF.
- Air conditioner switch is OFF.
- Rear window defogger switch is OFF.
- Steering wheel is in the straight-ahead position, etc.
4. Start engine and warm it up until engine coolant temperature
indicator points the middle of gauge.
Ensure engine stays below 1,000 rpm.
5. Run engine at about 2,000 rpm for about 2 minutes under no
load.
6. Make sure that no DTC is displayed with CONSULT-II or GST.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2.REPAIR OR REPLACE
Repair or replace components as necessary according to corresponding Diagnostic Procedure.
>> GO TO 3.
3.CHECK TARGET IDLE SPEED
With CONSULT-II
1. Run engine at about 2,000 rpm for about 2 minutes under no load.
SEF983U
SEF976U
SEF977U

EC-72
< SERVICE INFORMATION >
BASIC SERVICE PROCEDURE
2. Rev engine (2,000 to 3,000 rpm) two or three times under no
load, then run engine at idle speed for about 1 minute.
3. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Refer to EC-75, "
Idle Speed and Ignition Timing Check" .
Without CONSULT-II
1. Run engine at about 2,000 rpm for about 2 minutes under no load.
2. Rev engine (2,000 to 3,000 rpm) two or three times under no load, then run engine at idle speed for about
1 minute.
3. Check idle speed.
Refer to EC-75, "
Idle Speed and Ignition Timing Check" .
OK or NG
OK >> GO TO 10.
NG >> GO TO 4.
4.PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-77, "
Accelerator Pedal Released Position Learning" .
>> GO TO 5.
5.PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-77, "
Throttle Valve Closed Position Learning" .
>> GO TO 6.
6.PERFORM IDLE AIR VOLUME LEARNING
Refer to EC-78, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Ye s o r N o
Ye s > > G O T O 7 .
No >> 1. Follow the instruction of Idle Air Volume Learning.
2. GO TO 4.
7.CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
PBIA8513J
650 ± 50 rpm (in P or N position)
SEF058Y
650 ± 50 rpm (in P or N position)