ECU INFINITI QX56 2008 Factory Service Manual

EC-56
< FUNCTION DIAGNOSIS >[VK56DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
When there is an open circuit on MIL circuit, the ECM c
annot warn the driver by lighting up MIL when there is
malfunction on engine control system.
Therefore, when electrical controlled throttle and part of ECM related diagnoses are continuously detected as
NG for 5 trips, ECM warns the driver that engine cont rol system malfunctions and MIL circuit is open by means
of operating fail-safe function.
The fail-safe function also operates when above diagnos es except MIL circuit are detected and demands the
driver to repair the malfunction.
MIL Flashing Without DTC
When any SRT codes are not set, MIL may fl ash without DTC. For the details, refer to EC-462, "DTC Index".
HOW TO SWITCH DIAGNOSTIC TEST MODE
NOTE:
•It is better to count the ti me accurately with a clock.
• It is impossible to switch the di agnostic mode when an accelerator pedal position sensor circuit has
a malfunction.
• Always ECM returns to Diagnostic Test Mode I after ignition switch is turned OFF.
How to Set Diagnostic Test Mode II (Self-diagnostic Results)
1. Confirm that accelerator pedal is fully releas ed, turn ignition switch ON and wait 3 seconds.
2. Repeat the following procedure quickly five times within 5 seconds.
a. Fully depress the accelerator pedal.
b. Fully release the accelerator pedal.
3. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 10 seconds until the MIL starts blinking.
NOTE:
Do not release the accelerator pedal for 10 seconds if MIL may start blinking on the halfway of this
10 seconds. This blinking is displaying SRT status and is continued for another 10 seconds. For
the details, refer to EC-462, "
DTC Index".
Diagnostic Test
ModeKEY and ENG.
Status Function
Explanation of Function
Mode I Ignition switch in
ON position
Engine stopped BULB CHECK
This function checks the MIL bulb for damage (blown, open
circuit, etc.).
If the MIL does not come on, check MIL circuit.
Engine running MALFUNCTION WARNING This is a usual driving condition. When a malfunction is de-
tected twice in two consecutive driving cycles (two trip de-
tection logic), the MIL will light up to inform the driver that a
malfunction has been detected.
The following malfunctions will light up or blink the MIL in
the 1st trip.
• Misfire (Possible three way catalyst damage)
• One trip detection diagnoses
Mode II Ignition switch in
ON position
Engine stopped SELF-DIAGNOSTIC
RESULTS
This function allows DTCs an
d 1st trip DTCs to be read.
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut
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EC-58
< FUNCTION DIAGNOSIS >[VK56DE]
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-462, "
DTC Index")
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 memo ry before starting trouble diagnoses.
OBD System Operation ChartINFOID:0000000001351327
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 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-41, "
Two Trip Detection Logic".
• The MIL will go off after the vehicle is driven 3 time s (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-
tion System, the DTC and freeze frame data will be stored until the vehicle is driven 80 times (driving pattern
PBIB3005E
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ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-59
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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 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 "EXPLANATI ON 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 MisfireOther
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, *21 (pattern B)
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EC-60
< FUNCTION DIAGNOSIS >[VK56DE]
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 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
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EC-62
< FUNCTION DIAGNOSIS >[VK56DE]
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 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
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ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-63
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• 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 reac
hes 3 (*2 in OBD SYSTEM OPERATION CHART).
CONSULT-III Function (ENGINE)INFOID:0000000001351348
FUNCTION
*: The following emission-related diagnostic information is cleared when the ECM memory is erased.
• Diagnostic trouble codes
• 1st trip diagnostic trouble codes
• Freeze frame data
• 1st trip freeze frame data
• System readiness test (SRT) codes
•Test values
ENGINE CONTROL COMPONENT PARTS/CONTROL SYSTEMS APPLICATION
AEC574
Diagnostic test mode Function
Work support This mode enables a technician to adjust some devices faster and more accurately by following the in-
dications on the CONSULT-III unit.
Self-diagnostic results Self-diagnostic results such as 1st trip DTC, DTCs and 1st trip freeze frame data or freeze frame data
can be read and erased quickly.*
Data monitor Input/Output data in the ECM can be read.
Active test Diagnostic Test Mode in which CONSULT-III drives some actuators apart from the ECMs and also shifts
some parameters in
a specified range.
Function test This mode is used to inform customers when their vehicle condition requires periodic maintenance.
DTC & SRT confirmation The status of system monitoring tests and the self-diagnosis status/result can be confirmed.
ECU Identification ECM part number can be read.
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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 DTC and 1st trip DTC, refer to
EC-462, "DTC Index".
Freeze Frame Data and 1st Trip Freeze Frame Data
EVAP SYSTEM CLOSECLOSE 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 REGISTERED IN ECMWhen registering VIN in ECM
TARGET IDLE RPM ADJ* • IDLE CONDITION When setting target idle speed
TARGET IGN TIM ADJ* • IDLE CONDITION When 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 PXXX X. (Refer to
EC-462, "
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: March 2010
2008 QX56

EC-86
< COMPONENT DIAGNOSIS >[VK56DE]
POWER SUPPLY AND GROUND CIRCUIT
Check the following.
• Harness connectors F32, E2
• Harness for open or short between ECM and ground
>> Repair open circuit or short to power in harness or connectors.
16.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
OK or NG
OK >> Replace IPDM E/R.
NG >> Repair open circuit or short to power in harness or connectors.
Ground InspectionINFOID:0000000001351356
Ground connections are very important to the proper operation of electrical and electronic circuits. Ground
connections are often exposed to moisture, dirt and ot her corrosive elements. The corrosion (rust) can
become an unwanted resistance. This unwanted resistance can change the way a circuit works.
Electronically controlled circuits are very sensitive to proper grounding. A loose or corroded ground can drasti-
cally affect an electronically controlled circuit. A poor or corroded ground can easily affect the circuit. Even
when the ground connection looks clean, there can be a thin film of rust on the surface.
When inspecting a ground connection follow these rules:
• Remove the ground bolt or screw.
• Inspect all mating surfaces for tarnish, dirt, rust, etc.
• Clean as required to assure good contact.
• Reinstall bolt or screw securely.
• Inspect for “add-on” accessories which may be interfering with the ground circuit.
• If several wires are crimped into one ground eyelet terminal, check for proper crimps. Make sure all of the wires are clean, securely fastened and providing a good ground path. If multiple wires are cased in one eye-
let make sure no ground wires have excess wire insulation.
PBIB1870E
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EC-90
< COMPONENT DIAGNOSIS >[VK56DE]
P0011, P0021 IVT CONTROL
P0011, P0021 IVT CONTROL
On Board Diagn
osis LogicINFOID:0000000001351370
FA I L - S A F E M O D E
When the malfunction is detected, the ECM enters fail-safe mode.
DTC Confirmation ProcedureINFOID:0000000001351371
CAUTION:
Always drive at a safe speed.
NOTE:
•If DTC P0011 or P0021 is displayed with DTC P0075, P0081, P1140 or P1145, first perform the trouble
diagnosis for EC-103
or EC-299.
• If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confir m that battery voltage is between 10V and 16V at
idle.
PROCEDURE FOR MALFUNCTION A
With CONSULT-III
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-III.
3. Maintain the following conditions for at least 10 consecutive seconds.
4. Maintain the following conditions for at least 20 consecutive seconds.
DTC No. Trouble diagnosis name Detecting conditionPossible cause
P0011
0011
(Bank 1)
Intake valve timing control
performance A
The alignment of the intake valve timing
control has been misresistered. • Harness or connectors
(Intake valve timing control solenoid
valve circuit is open or shorted.)
• Harness or connectors (Intake valve timing control position
sensor circuit is open or shorted.)
• Intake valve timing control solenoid valve
• Intake valve timing control position sensor
• Crankshaft position sensor (POS)
• Camshaft position sensor (PHASE)
• Accumulation of debris to the signal pick-up portion of the camshaft
sprocket
• Timing chain installation
• Foreign matter caught in the oil groove for intake valve timing control
P0021
0021
(Bank 2)
B
There is a gap between angle of target and
phase-control angle degree.
Detected items
Engine operating condition in fail-safe mode
Intake valve timing control The signal is not energized to the solenoid valve and the valve control does not function
ENG SPEEDMore than 2,000 rpm (A cons tant rotation is maintained.)
COOLAN TEMP/S More than 70 °C (158 °F)
Selector lever 1st or 2nd position
Driving location uphill Driving vehicle uphill
(Increased engine load will help maintain the driving con-
ditions required for this test.)
Revision: March 2010
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P0011, P0021 IVT CONTROLEC-91
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5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to
EC-91, "
Diagnosis Procedure".
With GST
Follow the procedure “With CONSULT-III” above.
PROCEDURE FOR MALFUNCTION B
With CONSULT-III
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-III.
3. Maintain the following conditions for at least 10 consecutive seconds.
4. Check 1st trip DTC.
5. If 1st trip DTC is detected, go to EC-91, "
Diagnosis Procedure".
With GST
Follow the procedure “With CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000001351373
1.CHECK OIL PRESSURE WARNING LAMP
1. Start engine.
2. Check oil pressure warning lamp and confirm it is not illumi- nated.
OK or NG
OK >> GO TO 2.
NG >> Go to LU-8, "
Inspection".
2.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
ENG SPEED Idle
COOLAN TEMP/S More than 70 °C (158 °F)
Selector lever P or N position
ENG SPEED1,700 - 3,175 rpm (A constant rotation is maintained.)
COOLAN TEMP/S More than 70 °C (158 °F)
Selector lever 1st or 2nd position
Driving location uphill Driving vehicle uphill
(Increased engine load will help maintain the driving con-
ditions required for this test.)
PBIA8559J
Revision: March 2010
2008 QX56