2005 INFINITI QX4 ignition

EC-136Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
*: Leaving cooling fan OFF with CONSULT-II while engine is running may cause the engine to overheat.
DTC & SRT CONFIRMATION MODE
SRT STATUS Mode
For details, refer to EC-54, "SYSTEM READINESS TEST (SRT) CODE" .
SRT WORK SUPPORT Mode
This mode enables a technician to drive a vehicle to set the SRT while monitoring the SRT status.
DTC WORK SUPPORT Mode
*: DTC P1442 and P1456 does not apply to JA60 models but appears in DTC Work Support Mode screens.FUEL/T TEMP
SEN

Change the fuel tank temperature using CONSULT-II.
VENT CON-
TROL/V

Ignition switch: ON
(Engine stopped)

Turn solenoid valve ON and OFF
with the CONSULT-II and listen
to operating sound.Solenoid valve makes an operating
sound.
Harness and connectors

Solenoid valve TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
Test mode Test item Condition Reference page
EVAPORATIVE
SYSTEMPURG FLOW P0441
Refer to corresponding
trouble diagnosis for
DTC.EC-304
EVP SML LEAK P0442/P1442*EC-309
EVP V/S LEAK P0456/P1456*EC-357
PURG VOL CN/V P1444EC-531
A/F SEN1A/F SEN1 (B1) P1276EC-497A/F SEN1 (B2) P1286EC-497
A/F SEN1 (B1) P1278/P1279EC-507, EC-519
A/F SEN1 (B2) P1288/P1289EC-507, EC-519
HO2S2HO2S2 (B1) P0139EC-225
HO2S2 (B1) P1146EC-415
HO2S2 (B1) P1147EC-426
HO2S2 (B2) P0159EC-225
HO2S2 (B2) P1166EC-415
HO2S2 (B2) P1167EC-426

TROUBLE DIAGNOSIS
EC-139
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Revision: October 20052005 QX56
Generic Scan Tool (GST) FunctionUBS00L0C
DESCRIPTION
Generic Scan Tool (OBDII scan tool) complying with SAE J1978 has
8 different functions explained below.
ISO9141 is used as the protocol.
The name GST or Generic Scan Tool is used in this service manual.
FUNCTION
SEF 1 39 P
Diagnostic test mode Function
Service $01 READINESS TESTSThis diagnostic service gains access to current emission-related data values, including
analog 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-54, "
FREEZE FRAME DATA AND
1ST TRIP FREEZE FRAME DATA" .
Service $03 DTCsThis diagnostic service gains access to emission-related power train trouble codes which
were stored by ECM.
Service $04 CLEAR DIAG INFOThis diagnostic service can clear all emission-related diagnostic information. This
includes:

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.
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.

EC-140Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
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 the GST Operation Manual of
the tool maker.
BBIA0369E
SEF 3 98 S
SEF 4 16 S

TROUBLE DIAGNOSIS
EC-141
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Revision: October 20052005 QX56
CONSULT-II Reference Value in Data MonitorUBS00L0D
Remarks:

Specification data are reference values.

Specification data are output/input values which are detected or supplied by the ECM at the connector.
* Specification data may not be directly related to their components signals/values/operations.
i.e. Adjust ignition timing with a timing light before monitoring IGN TIMING, because the monitor may show the specification data in
spite of the ignition timing not being adjusted to the specification data. This IGN TIMING monitors the data calculated by the ECM
according to the signals input from the camshaft position sensor and other ignition timing related sensors.
MONITOR ITEM CONDITION SPECIFICATION
ENG SPEED

Run engine and compare CONSULT-II value with the tachometer indica-
tion.Almost the same speed as the
tachometer indication.
MAS A/F SE-B1 See EC-146, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
B/FUEL SCHDL See EC-146, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
A/F ALPHA-B1
A/F ALPHA-B2See EC-146, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
COOLAN TEMP/S

Engine: After warming up More than 70°C (158°F)
A/F SEN1 (B1)
A/F SEN1 (B2)

Engine: After warming upMaintaining engine speed at 2,000
rpmFluctuates around 1.5 V
HO2S2 (B1)
HO2S2 (B2)

Warm-up condition

After keeping engine speed
between 3,500 and 4,000 rpm for
1 minute and at idle for 1 minute
under no loadRevving engine from idle to 3,000 rpm
quickly0 - 0.3V ←→ Approx. 0.6 -
1.0V
HO2S2 MNTR (B1)
HO2S2 MNTR (B2)

Warm-up condition

After keeping engine speed
between 3,500 and 4,000 rpm for
1 minute and at idle for 1 minute
under no load.Revving engine from idle to 3,000 rpm
quickly.LEAN ←→ RICH
VHCL SPEED SE

Turn drive wheels and compare CONSULT-II value with the speedometer
indication.Almost the same speed as the
speedometer indication
BATTERY VOLT

Ignition switch: ON (Engine stopped) 11 - 14V
ACCEL SEN 1

Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released 0.5 - 1.0V
Accelerator pedal: Fully depressed 4.2 - 4.8V
ACCEL SEN 2*

Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released 0.5 - 1.0V
Accelerator pedal: Fully depressed 4.2 - 4.8V
THRTL SEN 1
THRTL SEN 2*

Ignition switch: ON
(Engine stopped)

Selector lever: DAccelerator pedal: Fully released More than 0.36V
Accelerator pedal: Fully depressed Less than 4.75V
EVAP SYS PRES

Ignition switch: ON Approx. 1.8 - 4.8V
START SIGNAL

Ignition switch: ON → START → ON OFF → ON → OFF
CLSD THL POS

Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released ON
Accelerator pedal: Slightly depressed OFF
AIR COND SIG

Engine: After warming up, idle
the engineAir conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor operates.)ON
P/N POSI SW

Ignition switch: ONSelector lever: P or N ON
Selector lever: Except above OFF
PW/ST SIGNAL

Engine: After warming up, idle
the engineSteering wheel: Not being turned
(Forward direction)OFF
Steering wheel: Being turned ON
LOAD SIGNAL

Ignition switch: ONRear window defogger switch is ON
and/or lighting switch is in 2nd.ON
Rear window defogger switch is OFF
and lighting switch is OFF.OFF

EC-142Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
IGNITION SW
Ignition switch: ON → OFF → ON ON → OFF → ON
HEATER FAN SW

Engine: After warming up, idle
the engineHeater fan: Not operating OFF
Heater fan: Operating ON
BRAKE SW

Ignition switch: ONBrake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
INJ PULSE-B1
INJ PULSE-B2

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No loadIdle 2.0 - 2.8 msec
2,000 rpm 1.9 - 2.9 msec
IGN TIMING

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No loadIdle 10° - 20° BTDC
2,000 rpm 25° - 45° BTDC
CAL/LD VALUE

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No loadIdle 14% - 33%
2,500 rpm 12% - 25%
MASS AIRFLOW

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No loadIdle 3.0 - 9.0 g·m/s
2,500 rpm 9.0 - 28.0 g·m/s
PURG VOL C/V

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No loadIdle
(Accelerator pedal: Not depressed
even slightly, after engine starting.)0%
2,000 rpm —
AIR COND RLY

Engine: After warming up, idle
the engineAir conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor: Operates)ON
FUEL PUMP RLY

For 1 second after turning ignition switch ON

Engine running or crankingON

Except above conditions OFF
VENT CONT/V

Ignition switch: ON OFF
THRTL RELAY

Ignition switch: ON ON
COOLING FAN

Engine: After warming up, idle
the engine

Air conditioner switch: OFFEngine coolant temperature: 99°C
(210°F) or lessOFF
Engine coolant temperature: 100°C
(212°F) or moreHI
HO2S2 HTR (B1)
HO2S2 HTR (B2)

Engine speed is below 3,600 rpm after the following conditions are met.
–Engine: After warming up
–Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute and
at idle for 1 minute under no loadON

Engine speed: Above 3,600 rpm OFF
I/P PULLY SPD

Vehicle speed: More than 20 km/h (12 MPH)Almost the same speed as the
tachometer indication
VEHICLE SPEED

Turn drive wheels and compare CONSULT-II value with the speedometer
indication.Almost the same speed as the
speedometer indication
TRVL AFTER MIL

Ignition switch: ONVehicle has traveled after MIL has
turned ON.0 - 65,535 km
(0 - 40,723 mile) MONITOR ITEM CONDITION SPECIFICATION

TROUBLE DIAGNOSIS
EC-143
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Revision: October 20052005 QX56
*: Accelerator pedal position sensor 2 signal and throttle position sensor 2 signal are converted by ECM internally. Thus, they differ from
ECM terminals voltage signal.A/F S1 HTR (B1)
A/F S1 HTR (B2)

Engine: After warming up, idle the engine 0 - 100%
AC PRESS SEN

Ignition switch: ON (Engine stopped) Approx. 0V

Engine: Idle

Air conditioner switch: ON1.0 - 4.0V
VHCL SPEED SE

Turn drive wheels and compare CONSULT-II value with the speedometer
indication.Almost the same speed as the
speedometer indication
SET VHCL SPD

Engine: Running ASCD: Operating.The preset vehicle speed is
displayed.
MAIN SW

Ignition switch: ONMAIN switch: Pressed ON
MAIN switch: Released OFF
CANCEL SW

Ignition switch: ONCANCEL switch: Pressed ON
CANCEL switch: Released OFF
RESUME/ACC SW

Ignition switch: ONRESUME/ACCELERATE switch:
PressedON
RESUME/ACCELERATE switch:
ReleasedOFF
SET SW

Ignition switch: ONSET/COAST switch: Pressed ON
SET/COAST switch: Released OFF
DIST SW

Ignition switch: ONDISTANCE switch: Pressed ON
DISTANCE switch: Released OFF
BRAKE SW1

Ignition switch: ONBrake pedal: Fully released ON
Brake pedal: Slightly depressed OFF
BRAKE SW2

Ignition switch: ONBrake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
CRUISE LAMP

Ignition switch: ONMAIN switch: Pressed at the 1st time
→ at the 2nd timeON → OFF
SET LAMP

MAIN switch: ON

Vehicle speed: Between 40 km/h
(25 MPH) and 144 km/h (89
MPH)ASCD: Operating ON
ASCD: Not operating OFF MONITOR ITEM CONDITION SPECIFICATION

EC-144Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
Major Sensor Reference Graph in Data Monitor ModeUBS00L0E
The following are the major sensor reference graphs in “DATA MONITOR” mode.
CLSD THL POS, ACCEL SEN 1, THRTL SEN 1
Below is the data for “CLSD THL POS”, “ACCEL SEN 1” and “THRTL SEN 1” when depressing the accelera-
tor pedal with the ignition switch ON and with selector lever in D position.
The signal of “ACCEL SEN 1” and “THRTL SEN 1” should rise gradually without any intermittent drop or rise
after “CLSD THL POS” is changed from ON to OFF.
ENG SPEED, MAS A/F SE-B1, THRTL SEN 1, HO2S2 (B1), INJ PULSE-B1
Below is the data for “ENG SPEED”, “MAS A/F SE-B1”, “THRTL SEN 1”, “HO2S2 (B1)” and “INJ PULSE-B1”
when revving engine quickly up to 4,800 rpm under no load after warming up engine sufficiently.
Each value is for reference, the exact value may vary.
PBIB0198E
PBIB2445E

TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-151
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Revision: October 20052005 QX56
10. DETECT MALFUNCTIONING PART
1. Check the following.
–Ignition coil and its circuit (Refer to EC-619, "IGNITION SIGNAL" .)
–Fuel injector and its circuit (Refer to EC-631, "INJECTOR CIRCUIT" .)
–Intake air leakage
–Low compression pressure (Refer to EM-58, "CHECKING COMPRESSION PRESSURE" .)
2. If NG, repair or replace the malfunctioning part.
If OK, replace fuel injector. (It may be caused by leakage from fuel injector or clogging.)
>> GO TO 11.
11 . CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG >> GO TO 12.
12. CHECK A/F SENSOR 1 FUNCTION
Perform all DTC Confirmation Procedure related with A/F sensor 1.

For DTC P1271, P1281, refer to EC-459, "DTC Confirmation Procedure" .

For DTC P1272, P1282, refer to EC-468, "DTC Confirmation Procedure" .

For DTC P1273, P1283, refer to EC-477, "DTC Confirmation Procedure" .

For DTC P1274, P1284, refer to EC-487, "DTC Confirmation Procedure" .

For DTC P1276, P1286, refer to EC-497, "DTC Confirmation Procedure" .

For DTC P1278, P1288, refer to EC-508, "DTC Confirmation Procedure" .

For DTC P1279, P1289, refer to EC-520, "DTC Confirmation Procedure" .
OK or NG
OK >> GO TO 15.
NG >> GO TO 13.
13. CHECK A/F SENSOR 1 CIRCUIT
Perform Diagnostic Procedure according to corresponding DTC.
>> GO TO 14.
14. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG >> GO TO 15.