ignition INFINITI QX4 2005 Factory Service Manual

EC-90Revision: October 2005
BASIC SERVICE PROCEDURE
2005 QX56
32. ERASE UNNECESSARY DTC
After this inspection, unnecessary DTC might be displayed.
Erase the stored memory in ECM and TCM. Refer to EC-62, "
HOW TO ERASE EMISSION-RELATED DIAG-
NOSTIC INFORMATION" and AT- 3 7 , "OBD-II Diagnostic Trouble Code (DTC)" .
>> GO TO 4.
33. CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of an incident, but
this is a rare case.)
2. Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs. Refer to
BL-139, "
ECM Re-communicating Function" .
>> GO TO 4.
VIN RegistrationUBS00KZX
DESCRIPTION
VIN Registration is an operation to registering VIN in ECM. It must be performed each time ECM is replaced.
NOTE:
Accurate VIN which is registered in ECM may be required for Inspection & Maintenance (I/M).
OPERATION PROCEDURE
With CONSULT-II
1. Check the VIN of the vehicle and note it. Refer to GI-46, "IDENTIFICATION INFORMATION" .
2. Turn ignition switch ON and engine stopped.
3. Select “VIN REGISTRATION” in “WORK SUPPORT” mode.
4. Follow the instruction of CONSULT-II display.
Accelerator Pedal Released Position LearningUBS00KZY
DESCRIPTION
Accelerator Pedal Released Position Learning is an operation to learn the fully released position of the accel-
erator pedal by monitoring the accelerator pedal position sensor output signal. It must be performed each time
harness connector of accelerator pedal position sensor or ECM is disconnected.
OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON and wait at least 2 seconds.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON and wait at least 2 seconds.
5. Turn ignition switch OFF and wait at least 10 seconds.
Throttle Valve Closed Position LearningUBS00KZZ
DESCRIPTION
Throttle Valve Closed Position Learning is an operation to learn the fully closed position of the throttle valve by
monitoring the throttle position sensor output signal. It must be performed each time harness connector of
electric throttle control actuator or ECM is disconnected.
PBIB2242E

BASIC SERVICE PROCEDURE
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Revision: October 20052005 QX56
OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON.
3. Turn ignition switch OFF wait at least 10 seconds.
Make sure that throttle valve moves during above 10 seconds by confirming the operating sound.
Idle Air Volume LearningUBS00L00
DESCRIPTION
Idle Air Volume Learning is an operation to learn the idle air volume that keeps each engine within the specific
range. It must be performed under any of the following conditions:

Each time electric throttle control actuator or ECM is replaced.

Idle speed or ignition timing is out of specification.
PREPARATION
Before performing Idle Air Volume Learning, make sure that all of the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are missed for even a moment.

Battery voltage: More than 12.9V (At idle)

Engine coolant temperature: 70 - 100°C (158 - 212°F)

Park/Neutral position (PNP) switch: ON

Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, if the parking brake is applied before the engine
is start the headlamp will not be illuminated.

Steering wheel: Neutral (Straight-ahead position)

Vehicle speed: Stopped

Transmission: Warmed-up
For models with CONSULT-II, drive vehicle until “ATF TEMP SE 1” in “DATA MONITOR” mode of “A/T”
system indicates less than 0.9V.
For models without CONSULT-II, drive vehicle for 10 minutes.
OPERATION PROCEDURE
With CONSULT-II
1. Perform EC-90, "Accelerator Pedal Released Position Learning" .
2. Perform EC-90, "
Throttle Valve Closed Position Learning" .
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic PREPARATION (previously mentioned) are in good order.
5. Select “IDLE AIR VOL LEARN” in “WORK SUPPORT” mode.
SEF 2 17 Z

EC-92Revision: October 2005
BASIC SERVICE PROCEDURE
2005 QX56
6. Touch “START” and wait 20 seconds.
7. Make sure that “CMPLT” is displayed on CONSULT-II screen. If
“CMPLT” is not displayed, Idle Air Volume Learning will not be
carried out successfully. In this case, find the cause of the inci-
dent by referring to the DIAGNOSTIC PROCEDURE below.
8. Rev up the engine two or three times and make sure that idle
speed and ignition timing are within the specifications.
Without CONSULT-II
NOTE:

It is better to count the time accurately with a clock.

It is impossible to switch the diagnostic mode when an accelerator pedal position sensor circuit
has a malfunction.
1. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
2. Perform EC-90, "
Throttle Valve Closed Position Learning" .
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic PREPARATION (previously mentioned) are in good order.
5. Turn ignition switch OFF and wait at least 10 seconds.
6. Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds.
7. Repeat the following procedure quickly five times within 5 seconds.
a. Fully depress the accelerator pedal.
b. Fully release the accelerator pedal.
8. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the MIL stops
blinking and turned ON.
9. Fully release the accelerator pedal within 3 seconds after the MIL turned ON.
10. Start engine and let it idle.
11. Wait 20 seconds.
12. Rev up the engine two or three times and make sure that idle speed and ignition timing are within the
specifications.
SEF 4 54 Y
ITEM SPECIFICATION
Idle speed 650 ± 50 rpm (in P or N position)
Ignition timing 15 ± 5° BTDC (in P or N position)
MBIB0238E
SEC8 97 C

BASIC SERVICE PROCEDURE
EC-93
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Revision: October 20052005 QX5613. If idle speed and ignition timing are not within the specification, Idle Air Volume Learning will not be carried
out successfully. In this case, find the cause of the incident by referring to the DIAGNOSTIC PROCE-
DURE below.
DIAGNOSTIC PROCEDURE
If idle air volume learning cannot be performed successfully, proceed as follows:
1.Check that throttle valve is fully closed.
2.Check PCV valve operation.
3.Check that downstream of throttle 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 eliminate the cause of the incident.
It is useful to perform EC-146, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
5.If any of the following conditions occur after the engine has started, eliminate the cause of the
incident and perform Idle Air Volume Learning all over again:

Engine stalls.

Erroneous idle.
Fuel Pressure CheckUBS00L01
FUEL PRESSURE RELEASE
With CONSULT-II
1. Turn ignition switch ON.
2. Perform “FUEL PRESSURE RELEASE” in “WORK SUPPORT”
mode with CONSULT-II.
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-II
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.
ITEM SPECIFICATION
Idle speed 650 ± 50 rpm (in P or N position)
Ignition timing 15 ± 5° BTDC (in P or N position)
SEF 2 14 Y
BBIA0380E

EC-94Revision: October 2005
BASIC SERVICE PROCEDURE
2005 QX56
FUEL PRESSURE CHECK
CAUTION:

Before disconnecting fuel line, release fuel pressure from fuel line to eliminate danger.

Be careful not to scratch or get the fuel hose connection area dirty when servicing, so that the
quick connector o-ring maintains sealability.

Use Fuel Pressure Gauge Kit J-44321 and Fuel Pressure Adapter J-44321-6 to check fuel pressure.

Do not perform fuel pressure check with electrical system operating (i.e. lights, rear defog, A/C,
etc.). Fuel pressure gauge may indicate false readings due to varying engine loads and changes in
manifold vacuum.
NOTE:
Prepare pans or saucers under the disconnected fuel line because the fuel may spill out. The fuel pres-
sure cannot be completely released because JA60 models do not have fuel return system.
1. Release fuel pressure to zero. Refer to EC-93, "
FUEL PRESSURE RELEASE" .
2. Remove engine cover.
3. Remove fuel hose using Quick Connector Release J-45488. Refer to EM-15, "
INTAKE MANIFOLD" .

Do not twist or kink fuel hose because it is plastic hose.

Do not remove fuel hose from quick connector.

Keep fuel hose connections clean.
4. Install Fuel Pressure Adapter J-44321-6 and Fuel Pressure
Gauge (from kit J-44321) as shown in figure.

Do not distort or bend fuel rail tube when installing fuel pres-
sure gauge adapter.

When reconnecting fuel hose, check the original fuel hose for
damage and abnormality.
5. Turn ignition switch ON (reactivate fuel pump), and check for
fuel leakage.
6. Start engine and check for fuel leakage.
7. Read the indication of fuel pressure gauge.

During fuel pressure check, check for fuel leakage from fuel
connection every 3 minutes.
8. If result is unsatisfactory, go to next step.
9. Check the following.

Fuel hoses and fuel tubes for clogging

Fuel filter for clogging

Fuel pump

Fuel pressure regulator for clogging
If OK, replace fuel pressure regulator.
If NG, repair or replace.
10. Before disconnecting Fuel Pressure Gauge and Fuel Pressure Adapter J-44321-6, release fuel pressure
to zero. Refer to EC-93, "
FUEL PRESSURE RELEASE" . At idling:
Approximately 350 kPa (3.57 kg/cm
2 , 51 psi)
BBIA0390E

TROUBLE DIAGNOSIS
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Revision: October 20052005 QX56
TROUBLE DIAGNOSISPFP:00004
Trouble Diagnosis IntroductionUBS00L02
INTRODUCTION
The engine has an ECM to control major systems such as fuel con-
trol, ignition control, idle air control system, etc. The ECM accepts
input signals from sensors and instantly drives actuators. It is essen-
tial that both input and output signals 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 the cause of the incidents. A road
test with CONSULT-II (or GST) or a circuit tester connected should
be performed. Follow the Work Flow on EC-96, "
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 EC-100, "
Worksheet Sample" 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.
MEF036D
SEF 2 33 G
SEF 2 34 G

TROUBLE DIAGNOSIS
EC-103
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Fail-safe ChartUBS00L04
When the DTC listed below is detected, the ECM enters fail-safe mode and the MIL lights up.

When there is an open circuit on MIL circuit, the ECM cannot 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 control system malfunctions and MIL circuit is open by
means of operating fail-safe function.
The fail-safe function also operates when above diagnoses except MIL circuit are detected and demands
the driver to repair the malfunction.
DTC No. Detected items Engine operating condition in fail-safe mode
P0102
P0103Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.
P0117
P0118Engine coolant tempera-
ture sensor circuitEngine coolant temperature will be determined by ECM based on the time after turning
ignition switch ON or START.
CONSULT-II displays the engine coolant temperature decided by ECM.
ConditionEngine coolant temperature decided
(CONSULT-II display)
Just as ignition switch is turned
ON or START40°C (104°F)
More than approx. 4 minutes after
ignition ON or START80°C (176°F)
Except as shown above40 - 80°C (104 - 176°F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cooling
fan operates while engine is running.
P0122
P0123
P0222
P0223
P2135Throttle position sensor The ECM controls the electric throttle control actuator in regulating the throttle opening in
order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal
condition.
So, the acceleration will be poor.
P1121 Electric throttle control
actuator(When electric throttle control actuator does not function properly due to the return spring
malfunction:)
ECM controls the electric throttle actuator by regulating the throttle opening around the
idle position. The engine speed will not rise more than 2,000 rpm.
(When throttle valve opening angle in fail-safe mode is not in specified range:)
ECM controls the electric throttle control actuator by regulating the throttle opening to 20
degrees or less.
(When ECM detects the throttle valve is stuck open:)
While the vehicle is driving, it slows down gradually by fuel cut. After the vehicle stops,
the engine stalls.
The engine can restart in N or P position, and engine speed will not exceed 1,000 rpm or
more.
P1122 Electric throttle control
functionECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P1124
P1126Throttle control motor relay ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P1128 Throttle control motor ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P1229 Sensor power supply ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2122
P2123
P2127
P2128
P2138Accelerator pedal position
sensorThe ECM controls the electric throttle control actuator in regulating the throttle opening in
order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal
condition.
So, the acceleration will be poor.
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut

EC-104Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
Symptom Matrix ChartUBS00L05
SYSTEM — BASIC ENGINE CONTROL SYSTEM
SYMPTOM
Refer-
ence page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Fuel Fuel pump circuit 1 1 2 3 2 2 2 3 2EC-637
Fuel pressure regulator system 3 3 4 4 4 4 4 4 4 4EC-94
Injector circuit 1 1 2 3 2 2 2 2EC-631
Evaporative emission system 3 3 4 4 4 4 4 4 4 4EC-32
Air Positive crankcase ventilation sys-
tem
334444444 41EC-45
Incorrect idle speed adjustment 1 1 1 1 1EC-72
Electric throttle control actuator 1 1 2 3 3 2 2 2 2 2 2EC-397
,
EC-399
,
EC-405
,
EC-410
Ignition Incorrect ignition timing adjustment 3 3 1 1 1 1 1 1EC-72
Ignition circuit 1 1 2 2 2 2 2 2EC-619
Main power supply and ground circuit 2 2 3 3 3 3 3 2 3EC-157
Mass air flow sensor circuit
1
122
222 2EC-174,
EC-183
Engine coolant temperature sensor circuit
333EC-195,
EC-208
Air fuel ratio (A/F) sensor 1 circuitEC-459
,
EC-468
,
EC-477
,
EC-487
,
EC-497
,
EC-507
,
EC-519
Throttle position sensor circuit
22EC-201
,
EC-264
,
EC-450
,
EC-452
,
EC-604
Accelerator pedal position sensor circuit 3 2 1EC-454
,
EC-591
,
EC-597
,
EC-611
Knock sensor circuit 2 3EC-279
Crankshaft position sensor (POS) circuit 2 2EC-284

EC-118Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
3LThrottle control motor relay
power supply[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
4 L/W Throttle control motor (Close)[Ignition switch: ON]

Engine: Stopped

Selector lever: D

Accelerator pedal: Fully released0 - 14V
5 L/B Throttle control motor (Open)[Ignition switch: ON]

Engine: Stopped

Selector lever: D

Accelerator pedal: Fully depressed0 - 14V
6GRHeated oxygen sensor 2
heater (bank 1)[Engine is running]

Warm-up condition

Engine speed is below 3,600 rpm after the
following conditions are met.
–Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load0 - 1.0V
[Ignition switch: ON]

Engine: Stopped
[Engine is running]

Engine speed: Above 3,600 rpmBATTERY VOLTAGE
(11 - 14V)
12 RPower steering pressure sen-
sor[Engine is running]

Steering wheel: Being turned0.5 - 4.5V
[Engine is running]

Steering wheel: Not being turned0.4 - 0.8V
13 OCrankshaft position sensor
(POS)[Engine is running]

Warm-up condition

Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idleApproximately 10V
[Engine is running]

Engine speed: 2,000 rpmApproximately 10V TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
PBIB1104E
PBIB1105E
PBIB1041E
PBIB1042E

EC-120Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
25 O/GHeated oxygen sensor 2
heater (bank 2)[Engine is running]

Warm-up condition

Engine speed is below 3,600 rpm after the
following conditions are met.
–Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load0 - 1.0V
[Ignition switch: ON]

Engine: Stopped
[Engine is running]

Engine speed: Above 3,600 rpmBATTERY VOLTAGE
(11 - 14V)
32 LEVAP control system pres-
sure sensor[Ignition switch: ON]Approximately 1.8 - 4.8V
34 R/B Intake air temperature sensor[Engine is running]Approximately 0 - 4.8V
Output voltage varies with intake
air temperature.
36 W Knock sensor (bank 2)[Engine is running]

Idle speedApproximately 2.5V
40
41
42
63Y/G
P
L
GInjector No. 6
Injector No. 4
Injector No. 2
Injector No. 8[Engine is running]

Warm-up condition

Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idleBATTERY VOLTAGE
(11 - 14V)
[Engine is running]

Warm-up condition

Engine speed: 2,000 rpmBATTERY VOLTAGE
(11 - 14V)
45 L/YEVAP canister purge volume
control solenoid valve[Engine is running]

Idle speed

Accelerator pedal: Not depressed even
slightly, after engine startingBATTERY VOLTAGE
(11 - 14V)
[Engine is running]

Engine speed: About 2,000 rpm (More than
100 seconds after starting engine)BATTERY VOLTAGE
(11 - 14V) TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
SEC984C
SEC985C
SEC990C
SEC991C