2009 INFINITI QX56 200

ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-69
< FUNCTION DIAGNOSIS > [VK56DE]
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PURG VOL C/V [%]
 Indicates the EVAP canister purge vol-
ume control solenoid valve control value
computed by the ECM according to the
input signals.
 The opening becomes larger as the val- ue increases.
INT/V TIM (B1)
[ ° CA]
 Indicates [°CA] of intake camshaft ad-
vanced angle.
INT/V TIM (B2)
[ ° CA]
INT/V SOL (B1) [%]  The control value of the intake valve tim- ing control solenoid valve (determined by
ECM according to the input signals) is in-
dicated.
 The advance angle becomes larger as
the value increases.
INT/V SOL (B2) [%]
AIR COND RLY
[ON/OFF]
 The air conditioner relay control condi-
tion (determined by ECM according to
the input signals) is indicated.
FUEL PUMP RLY
[ON/OFF]  Indicates the fuel pump relay control con-
dition determined by ECM according to
the input signals.
VENT CONT/V
[ON/OFF]  The control condition of the EVAP canis-
ter vent control valve (determined by
ECM according to the input signals) is in-
dicated.
ON: Closed
OFF: Open
THRTL RELAY [ON/
OFF] × Indicates the throttle control motor relay
control condition determined by the ECM
according to the input signals.
COOLING FAN
[HI/OFF] × The control condition of the cooling fan
(determined by ECM according to the in-
put signals) is indicated.
HI: High speed operation
OFF: Stop
HO2S2 HTR (B1)
[ON/OFF]  Indicates [ON/OFF] condition of heated
oxygen sensor 2 heater determined by
ECM according to the input signals.
HO2S2 HTR (B2)
[ON/OFF]
I/P PULLY SPD
[rpm]  Indicates the engine speed computed
from the input speed sensor signal.
VEHICLE SPEED
[km/h] or [mph]  Indicates the vehicle speed computed
from the output speed sensor signal.
IDL A/V LEARN
[YET/CMPLT]  Display the condition of idle air volume
learning
YET: Idle Air Volume Learning has not
been performed yet.
CMPLT: Idle Air Volume Learning has al-
ready been performed successfully.
TRVL AFTER MIL
[km] or [mile]  Distance traveled while MIL is activated.
Monitored item
[Unit] ECM IN-
PUT SIG-
NALS MAIN
SIGNALS Description Remarks
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EC-70
< FUNCTION DIAGNOSIS >[VK56DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
ACTIVE TEST MODE
Test Item
A/F S1 HTR (B1)
[%] A/F sensor 1 heater control value com-
puted by ECM according to the input sig-
nals.
 The current flow to the heater becomes larger as the value increases.
A/F S1 HTR (B2)
[%]
AC PRESS SEN [V]
 The signal voltage from the refrigerant
pressure sensor is displayed.
VHCL SPEED SE
[km/h] or [mph]  The vehicle speed computed from the
vehicle speed signal sent from combina-
tion meter is displayed.
SET VHCL SPD
[km/h] or [mph]  The preset vehicle speed is displayed.
MAIN SW
[ON/OFF]  Indicates [ON/OFF] condition from MAIN
switch signal.
CANCEL SW
[ON/OFF]  Indicates [ON/OFF] condition from CAN-
CEL switch signal.
RESUME/ACC SW
[ON/OFF]  Indicates [ON/OFF] condition from RE-
SUME/ACCELERATE switch signal.
SET SW
[ON/OFF]  Indicates [ON/OFF] condition from SET/
COAST switch signal.
BRAKE SW1
[ON/OFF]  Indicates [ON/OFF] condition from
ASCD brake switch signal.
BRAKE SW2
[ON/OFF]  Indicates [ON/OFF] condition of stop
lamp switch signal.
DIST SW
[ON/OFF]  Indicates [ON/OFF] condition from DIS-
TANCE switch signal.
ALT DUTY [%]  Indicates the duty ratio of the power gen-
eration command value. The ratio is cal-
culated by ECM based on the battery
current sensor signal.
BAT CUR SEN [mV]  The signal voltage of battery current sen-
sor is displayed.
ALT DUTY SIG
[ON/OFF]  The control condition of the power gener-
ation voltage variable control (deter-
mined by ECM according to the input
signals) is indicated.
ON: Power generation voltage variable
control is active.
OFF: Power generation voltage variable
control is inactive.
A/F ADJ-B1  Indicates the correction factor stored in ECM. The factor is calculated from the
difference between the target air/fuel ra-
tio stored in ECM and the air-fuel ratio
calculated from air fuel ratio (A/F) sensor
1 signal.
A/F ADJ-B2 Monitored item
[Unit] ECM IN-
PUT SIG-
NALS MAIN
SIGNALS Description Remarks
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ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-71
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*: 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
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EC-72
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ON BOARD DIAGNOSTIC (OBD) SYSTEM
*: DTC P1442 and P1456 does not apply to JA60 models but appears in DTC Work Support Mode screens.
Generic Scan Tool (GST) FunctionINFOID:0000000003771319
DESCRIPTION
Generic Scan Tool (OBDII scan tool) complying with SAE J1978 has
8 different functions explained below.
ISO15765-4 is used as the protocol.
The name GST or Generic Scan Tool is used in this service manual.
FUNCTION
Test mode Test item Corresponding DTC No. Reference page
EVAPORATIVE
SYSTEM PURG FLOW P0441 P0441
EC-210
EVP SML LEAK P0442/P1442*P0442
EC-215P0455EC-250
EVP V/S LEAK P0456/P1456* P0456 EC-257
PURG VOL CN/V P1444 P0443EC-222
A/F SEN1A/F SEN1 (B1) P1276 P0130
EC-136A/F SEN1 (B1) P1278/P1279 P0133EC-146
A/F SEN1 (B2) P1286 P0150EC-136
A/F SEN1 (B2) P1288/P1289 P0153EC-146
HO2S2HO2S2 (B1) P0139 P0139
EC-164
HO2S2 (B1) P1146 P0138EC-157
HO2S2 (B1) P1147 P0137EC-152
HO2S2 (B2) P0159 P0159EC-164
HO2S2 (B2) P1166 P0158EC-157
HO2S2 (B2) P1167 P0157EC-152
SEF139P
Diagnostic test mode Function
Service $01 READINESS TESTS This diagnostic service gains access to current emission-related data values, including an-
alog 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-456, "DTC Index"
.
Service $03 DTCs This diagnostic service gains access to emission-related power train trouble codes which
were stored by ECM.
Service $04 CLEAR DIAG INFO This diagnostic service can clear all emission-related diagnostic information. This in-
cludes:
 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.
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ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-73
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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
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EC-74
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TROUBLE DIAGNOSIS - SPECIFICATION VALUE
COMPONENT DIAGNOSIS
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
DescriptionINFOID:0000000003771320
The specification (SP) value indicates the tolerance of
the value that is displayed in “SPEC” of “DATA MONI-
TOR” mode with CONSULT-III during normal operation of the Engine Control System. When the value in
“SPEC” of “DATA MONITOR” mode is within the SP value, the Engine Control System is confirmed OK. When
the value in “SPEC” of “DATA MONITOR” mode is NO T within the SP value, the Engine Control System may
have one or more malfunctions.
The SP value is used to detect malfunctions that may af fect the Engine Control System, but will not light the
MIL.
The SP value will be displayed for the following three items:
 B/FUEL SCHDL (The fuel injection pulse width progr ammed into ECM prior to any learned on board correc-
tion)
 A/F ALPHA-B1/B2 (The mean value of air-fuel ratio feedback correction factor per cycle)
 MAS A/F SE-B1 (The signal voltage of the mass air flow sensor)
Testing ConditionINFOID:0000000003771321
 Vehicle driven distance: More than 5,000 km (3,107 miles)
 Barometric pressure: 98.3 - 104.3 kPa (1.003 - 1.064 kg/cm
2 , 14.25 - 15.12 psi)
 Atmospheric temperature: 20 - 30 °C (68 - 86 °F)
 Engine coolant temperature: 75 - 95 °C (167 - 203 °F)
 Engine speed: Idle
 Transmission: Warmed-up
- After the engine is warmed up to normal operating temper ature, drive vehicle until “ATF TEMP SE 1” (A/T
fluid temperature sensor signal) indicates more than 60 °C (140 °F).
 Electrical load: Not applied
- Rear window defogger switch, air conditioner switch, lighting switch are OFF. Steering wheel is straight
ahead.
Inspection ProcedureINFOID:0000000003771322
NOTE:
Perform “SPEC” in “DATA MONITOR” mode in maximum scale display.
1. Perform EC-13, "Basic Inspection"
.
2. Confirm that the testing conditions indicated above are met.
3. Select “B/FUEL SCHDL”, “A/F ALPHA-B1”, “A/F ALPHA-B2” and “MAS A/F SE-B1” in “SPEC” of “DATA
MONITOR” mode with CONSULT-III.
4. Make sure that monitor items are within the SP value.
5. If NG, go to EC-75, "Diagnosis Procedure"
.
Revision: December 20092009 QX56

TROUBLE DIAGNOSIS - SPECIFICATION VALUEEC-75
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Diagnosis ProcedureINFOID:0000000003771323
OVERALL SEQUENCE
PBIB2268E
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EC-76
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TROUBLE DIAGNOSIS - SPECIFICATION VALUE
DETAILED PROCEDURE
1.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Confirm that the testing conditions are met. Refer to EC-74, "Testing Condition"
.
3. 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.
NOTE:
PBIB3214E
Revision: December 20092009 QX56