2009 INFINITI QX56 ignition

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-456, "DTC Index".
Freeze Frame Data and 1st Trip Freeze Frame Data
EVAP SYSTEM CLOSE CLOSE 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 REGI STERED IN ECM When registering VIN in ECM
TARGET IDLE RPM ADJ*  IDLE CONDITION When setting target idle speed
TARGET IGN TIM ADJ*  IDLE CONDITION Wh en 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 PXXXX. (Refer to
EC-456, "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: December 20092009 QX56

EC-68
< FUNCTION DIAGNOSIS >[VK56DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
TP SEN 1-B1 [V]
××
 The throttle position sensor signal volt-
age is displayed.  TP SEN 2-B1 signal is converted by
ECM internally. Thus, it differs from
ECM terminal voltage signal.
TP SEN 2-B1 [V]
××
FUEL T/TMP SE
[ ° C] or [ °F]  The fuel temperature (determined by the
signal voltage of the fuel tank tempera-
ture sensor) is displayed.
INT/A TEMP SE
[ ° C] or [ °F] ××  The intake air temperature (determined
by the signal voltage of the intake air
temperature sensor) is indicated.
EVAP SYS PRES
[V]  The signal voltage of EVAP control sys-
tem pressure sensor is displayed.
FUEL LEVEL SE [V] × The signal voltage of the fuel level sen-
sor is displayed.
START SIGNAL
[ON/OFF]  Indicates start signal status [ON/OFF]
computed by the ECM according to the
signals of engine speed and battery volt-
age.  After starting the engine, [OFF] is dis-
played regardless of the starter signal.
CLSD THL POS
[ON/OFF] ×× Indicates idle position [ON/OFF] comput-
ed by ECM according to the accelerator
pedal position sensor signal.
AIR COND SIG
[ON/OFF] ×× Indicates [ON/OFF] condition of the air
conditioner switch as determined by the
air conditioner signal.
P/N POSI SW
[ON/OFF] ××
 Indicates [ON/OFF] condition from the
transmission range signal.
PW/ST SIGNAL
[ON/OFF] ×× [ON/OFF] condition of the power steering
system (determined by the signal voltage
of the power steering pressure sensor
signal) is indicated.
LOAD SIGNAL [ON/
OFF] ×× Indicates [ON/OFF] condition from the
electrical load signal.
ON: Rear window defogger switch is ON
and/or lighting switch is in 2nd position.
OFF: Both rear window defogger switch
and lighting switch are OFF.
IGNITION SW
[ON/OFF] ×× Indicates [ON/OFF] condition from igni-
tion switch signal.
HEATER FAN SW
[ON/OFF] ×
 Indicates [ON/OFF] condition from heat-
er fan switch signal.
BRAKE SW
[ON/OFF]  Indicates [ON/OFF] condition from the
stop lamp switch signal.
INJ PULSE-B1
[msec]  Indicates the actual fuel injection pulse
width compensated by ECM according to
the input signals.  When the engine is stopped, a certain
computed value is indicated.
INJ PULSE-B2
[msec]
IGN TIMING [BT-
DC]  Indicates the ignition timing computed by
ECM according to the input signals.  When the engine is stopped, a certain
value is indicated.
CAL/LD VALUE [%]
 “Calculated load value” indicates the val- ue of the current air flow divided by peak
air flow.
MASS AIRFLOW
[g·m/s]  Indicates the mass air flow computed by
ECM according to the signal voltage of
the mass air flow sensor.
Monitored item
[Unit] ECM IN-
PUT SIG-
NALS MAIN
SIGNALS Description Remarks
Revision: December 20092009 QX56

ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-71
< FUNCTION DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
*: Leaving cooling fan OFF with CONSULT-III while engine is running may cause the engine to overheat.
DTC & SRT CONFIRMATION MODE
SRT STATUS Mode
For details, refer to
EC-456, "DTC Index".
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
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
FUEL INJEC-
TION  Engine: Return to the original
trouble condition
 Change the amount of fuel injec-
tion using CONSULT-III. If trouble symptom disappears, see
CHECK ITEM.
 Harness and connectors
 Fuel injector
 Air fuel ratio (A/F) sensor 1
IGNITION TIM-
ING  Engine: Return to the original
trouble condition
 Timing light: Set
 Retard the ignition timing using
CONSULT-III. If trouble symptom disappears, see
CHECK ITEM.
 Perform Idle Air Volume Learning.
POWER BAL-
ANCE  Engine: After warming up, idle the
engine.
 A/C switch: OFF
 Selector lever: P or N
 Cut off each injector signal one at a time using CONSULT-III. Engine runs rough or dies.
 Harness and connectors
 Compression
 Fuel injector
 Power transistor
Spark plug
 Ignition coil
COOLING FAN*  Ignition switch: ON
 Turn the cooling fan HI and OFF
using CONSULT-III. Cooling fan moves and stops.  Harness and connectors
 Cooling fan motor
IPDM E/R
ENG COOLANT
TEMP  Engine: Return to the original
trouble condition
 Change the engine coolant tem- perature using CONSULT-III. If trouble symptom disappears, see
CHECK ITEM.  Harness and connectors
 Engine coolant temperature sen-
sor
 Fuel injector
FUEL PUMP RE-
LAY  Ignition switch: ON
(Engine stopped)
 Turn the fuel pump relay ON and OFF using CONSULT-III and lis-
ten to operating sound. Fuel pump relay makes the operat-
ing sound.
 Harness and connectors
 Fuel pump relay
PURG VOL
CONT/V  Engine: After warming up, run en-
gine at 1,500 rpm.
 Change the EVAP canister purge
volume control solenoid valve
opening percent using CON-
SULT-III. Engine speed changes according to
the opening percent.
 Harness and connectors
 Solenoid valve
FUEL/T TEMP
SEN  Change the fuel tank temperature using CONSULT-III.
VENT CON-
TROL/V  Ignition switch: ON
(Engine stopped)
 Turn solenoid valve ON and OFF with the CONSULT-III and listen
to operating sound. Solenoid valve makes an operating
sound.
 Harness and connectors
 Solenoid valve
V/T ASSIGN AN-
GLE  Engine: Return to the original
trouble condition
 Change intake valve timing using
CONSULT-III. If trouble symptom disappears, see
CHECK ITEM.
 Harness and connectors
 Intake valve timing control sole-
noid valve
ALTERNATOR
DUTY  Engine: Idle
 Change duty ratio using CON-
SULT-III. Battery voltage changes.  Harness and connectors
IPDM E/R
 Alternator
Revision: December 20092009 QX56

ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-73
< FUNCTION DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
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 th e GST Operation Manual of
the tool maker.
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.
Diagnostic test mode Function
BBIA0369E
SEF398S
SEF416S
Revision: December 20092009 QX56

EC-78
< COMPONENT DIAGNOSIS >[VK56DE]
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
>> GO TO 8.
8.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F AL PHA-B2” in “SPEC” of “DATA MONITOR” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >> INSPECTION END
NG >> GO TO 9.
9.PERFORM POWER BALANCE TEST
1. Perform “POWER BALANCE” in “ACTIVE TEST” mode.
2. Make sure that the each cylinder produces a momentary engine speed drop.
OK or NG
OK >> GO TO 12.
NG >> GO TO 10.
10.DETECT MALFUNCTIONING PART
1. Check the following.
- Ignition coil and its circuit (Refer to EC-404, "Diagnosis Procedure"
.)
- Fuel injector and its circuit (Refer to EC-392, "Diagnosis Procedure"
.)
- Intake air leakage
- Low compression pressure (Refer to EM-23, "Checking Compression Pressure"
.)
2. If NG, repair or replace the malfunctioning part.
If OK, replace fuel injector. (It may be caus ed 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 AL PHA-B2” in “SPEC” of “DATA MONITOR” 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 P0130, P0150, refer to EC-136, "DTC Confirmation Procedure"
.
 For DTC P0131, P0151, refer to EC-140, "DTC Confirmation Procedure"
.
 For DTC P0132, P0132, refer to EC-143, "DTC Confirmation Procedure"
.
 For DTC P0133, P0153, refer to EC-146, "DTC Confirmation Procedure"
.
 For DTC P2A00, P2A03, refer to EC-377, "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 AL PHA-B2” in “SPEC” of “DATA MONITOR” mode, and make sure that the
each indication is within the SP value.
OK or NG
Revision: December 20092009 QX56

EC-80
< COMPONENT DIAGNOSIS >[VK56DE]
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
2. Disconnect mass air flow sensor harness connector. Check pin terminal and connector for damage and
then reconnect it again.
>> GO TO 22.
22.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F AL PHA-B2” in “SPEC” of “DATA MONITOR” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >> 1. Detect malfunctioning part of mass air flow sensor circuit and repair it. Refer to EC-109 .
2. GO TO 29.
NG >> GO TO 23.
23.CHECK “MAS A/F SE-B1”
Select “MAS A/F SE-B1” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within the
SP value.
OK or NG
OK >> GO TO 24.
NG (More than the SP value)>>Replace mass air flow sensor, and then GO TO 29.
24.REPLACE ECM
1. Replace ECM.
2. Perform initialization of IVIS(NAT S) system and registration of all IVIS(NATS) ignition key IDs. Refer to
SEC-6, "ECM RE-COMMUNICATING FUNCT ION : Special Repair Requirement"
.
3. Perform EC-17, "VIN Registration"
.
4. Perform EC-18, "Accelerator Pedal Released Position Learning"
.
5. Perform EC-18, "Throttle Valve Closed Position Learning"
.
6. Perform EC-18, "Idle Air Volume Learning"
.
>> GO TO 29.
25.CHECK INTAKE SYSTEM
Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.
 Crushed air ducts
 Malfunctioning seal of air cleaner element
 Uneven dirt of air cleaner element
 Improper specification of intake air system
OK or NG
OK >> GO TO 27.
NG >> Repair or replace malfunctioning part, and then GO TO 26.
26.CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within the
SP value.
OK or NG
OK >> INSPECTION END
NG (Less than the SP value)>>GO TO 27.
27.CHECK “MAS A/F SE-B1”
Select “MAS A/F SE-B1” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within the
SP value.
OK or NG
OK >> GO TO 28.
NG (Less than the SP value)>>Replace mass air flow sensor, and then GO TO 30.
28.CHECK INTAKE SYSTEM
Check for the cause of air leak after the mass air flow sensor. Refer to the following.
Revision: December 20092009 QX56

EC-82
< COMPONENT DIAGNOSIS >[VK56DE]
POWER SUPPLY AND GROUND CIRCUIT
POWER SUPPLY AND GROUND CIRCUIT
Diagnosis ProcedureINFOID:0000000003771324
1.INSPECTION START
Start engine.
Is engine running?
Ye s o r N o
Ye s > > G O T O 8 .
No >> GO TO 2.
2.CHECK ECM POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF and then ON.
2. Check voltage between ECM terminal 109 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
 10A fuse
 Harness for open or short between ECM and fuse
>> Repair harness or connectors.
4.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-85, "Ground Inspection"
.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace ground connections.
5.CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-I
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminals 1, 115, 116 and ground. Refer to Wiring Diagram.
3. Also check harness for short to power. Voltage: Battery voltage
MBIB0015E
BBIA0354E
Continuity should exist.
Revision: December 20092009 QX56

POWER SUPPLY AND GROUND CIRCUITEC-83
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6.DETECT MALFUNCTIONING PART
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.
7.CHECK ECM POWER SUPPLY CIRCUIT-II
1. Reconnect ECM harness connector.
2. Turn ignition switch ON.
3. Check voltage between IPDM E/R terminal 4 and ground with CONSULT-III or tester.
OK or NG
OK >> Go to EC-404, "Diagnosis Procedure" .
NG >> GO TO 8.
8.CHECK ECM POWER SUPPLY CIRCUIT-III
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON and then OFF.
3. Check voltage between ECM terminals 119, 120 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 13.
NG (Battery voltage does not exist.)>>GO TO 9.
NG (Battery voltage exists for more than a few seconds.)>>GO TO 11 .
9.CHECK ECM POWER SUPPLY CIRCUIT-IV
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Check voltage between ECM terminal 111 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 10.
NG >> GO TO 11.
10.CHECK ECM POWER SUPPLY CIRCUIT-V
1. Disconnect ECM harness connector.
2. Disconnect IPDM E/R harness connector E119.
3. Check harness continuity between ECM terminals 119, 120 and IPDM E/R terminal 3. Voltage: Battery voltage
PBIB2063E
Voltage: After turning ignition switch OFF, battery
voltage will exist for a few seconds, then drop
approximately 0V.
PBIB1630E
Voltage: Battery voltage
PBIB1191E
Revision: December 20092009 QX56