2004 INFINITI QX56 knock sensor

EC-10Revision: August 2007
INDEX FOR DTC
2004 QX56
FUEL SYS-RICH-B1 P0172 0172 2×EC-217
FUEL SYS-RICH-B2 P0175 0175 2×EC-217
HLR/C SOL FNCTN P1769 1769 1×AT-166
HLR/C SOL/CIRC P1767 1767 1×AT-163
HO2S2 (B1) P0138 0138 2×EC-186
HO2S2 (B1) P0139 0139 2×EC-196
HO2S2 (B1) P1146 1146 2×EC-383
HO2S2 (B1) P1147 1147 2×EC-395
HO2S2 (B2) P0158 0158 2×EC-186
HO2S2 (B2) P0159 0159 2×EC-196
HO2S2 (B2) P1166 1166 2×EC-383
HO2S2 (B2) P1167 1167 2×EC-395
HO2S2 HTR (B1) P0037 0037 2×EC-138
HO2S2 HTR (B1) P0038 0038 2×EC-138
HO2S2 HTR (B2) P0057 0057 2×EC-138
HO2S2 HTR (B2) P0058 0058 2×EC-138
I/C SOLENOID/CIRC P1752 1752 1×AT-145
I/C SOLENOID FNCTN P1754 1754 1×AT-148
IAT SEN/CIRCUIT P0112 0112 2×EC-161
IAT SEN/CIRCUIT P0113 0113 2×EC-161
IAT SENSOR P0127 0127 2×EC-181
ISC SYSTEM P0506 0506 2×EC-342
ISC SYSTEM P0507 0507 2×EC-344
KNOCK SEN/CIRC-B1 P0327 0327 2 —EC-250
KNOCK SEN/CIRC-B1 P0328 0328 2 —EC-250
KNOCK SEN/CIRC-B2 P0332 0332 2 —EC-250
KNOCK SEN/CIRC-B2 P0333 0333 2 —EC-250
L/PRESS SOL/CIRC P0745 0745 2×AT-124
LC/B SOLENOID FNCT P1774 1774 1×AT-172
LC/B SOLENOID/CIRC P1772 1772 1×AT-169
MAF SEN/CIRCUIT P0101 0101 1×EC-146
MAF SEN/CIRCUIT P0102 0102 1×EC-154
MAF SEN/CIRCUIT P0103 0103 1×EC-154
MULTI CYL MISFIRE P0300 0300 2×EC-243
NATS MALFUNCTION P1610 - P1615 1610 - 1615 2 —BL-138
NO DTC IS DETECTED.
FURTHER TESTING
MAY BE REQUIRED.P0000 0000———
P-N POS SW/CIRCUIT P1706 1706 2×EC-546
PNP SW/CIRC P0705 0705 2×AT-109
PURG VOLUME CONT/V P0444 0444 2×EC-285
PURG VOLUME CONT/V P0445 0445 2×EC-285
PURG VOLUME CONT/V P1444 1444 2×EC-496
Items
(CONSULT-II screen terms)DTC*
1
TripMIL lighting
upReference page
CONSULT-II
GST*
2ECM*3

INDEX FOR DTC
EC-13
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Revision: August 20072004 QX56P0304 0304 CYL 4 MISFIRE 2×EC-243
P0305 0305 CYL 5 MISFIRE 2×EC-243
P0306 0306 CYL 6 MISFIRE 2×EC-243
P0307 0307 CYL 7 MISFIRE 2×EC-243
P0308 0308 CYL 8 MISFIRE 2×EC-243
P0327 0327 KNOCK SEN/CIRC-B1 2 —EC-250
P0328 0328 KNOCK SEN/CIRC-B1 2 —EC-250
P0332 0332 KNOCK SEN/CIRC-B2 2 —EC-250
P0333 0333 KNOCK SEN/CIRC-B2 2 —EC-250
P0335 0335 CKP SEN/CIRCUIT 2×EC-255
P0340 0340 CMP SEN/CIRC-B1 2×EC-261
P0420 0420 TW CATALYST SYS-B1 2×EC-267
P0430 0430 TW CATALYST SYS-B2 2×EC-267
P0441 0441 EVAP PURG FLOW/MON 2×EC-271
P0442 0442 EVAP SMALL LEAK 2×EC-276
P0444 0444 PURG VOLUME CONT/V 2×EC-285
P0445 0445 PURG VOLUME CONT/V 2×EC-285
P0447 0447 VENT CONTROL VALVE 2×EC-292
P0451 0451 EVAP SYS PRES SEN 2×EC-299
P0452 0452 EVAP SYS PRES SEN 2×EC-302
P0453 0453 EVAP SYS PRES SEN 2×EC-308
P0455 0455 EVAP GROSS LEAK 2×EC-316
P0456 0456 EVAP VERY SML LEAK 2×EC-324
P0460 0460 FUEL LEV SEN SLOSH 2×EC-334
P0461 0461 FUEL LEVEL SENSOR 2×EC-336
P0462 0462 FUEL LEVL SEN/CIRC 2×EC-338
P0463 0463 FUEL LEVL SEN/CIRC 2×EC-338
P0500 0500
VEH SPEED SEN/CIRC*52×EC-340
P0506 0506 ISC SYSTEM 2×EC-342
P0507 0507 ISC SYSTEM 2×EC-344
P0550 0550 PW ST P SEN/CIRC 2 —EC-346
P0605 0605 ECM 1 or 2× or —EC-351
P0700 0700 TCM 1×AT- 1 0 8
P0705 0705 PNP SW/CIRC 2×AT- 1 0 9
P0710 0710 ATF TEMP SEN/CIRC 2×AT- 1 3 1
P0720 0720
VEH SPD SEN/CIR AT*52×AT - 11 2
P0740 0740 TCC SOLENOID/CIRC 2×AT - 11 8
P0744 0744 A/T TCC S/V FNCTN 2×AT- 1 2 1
P0745 0745 L/PRESS SOL/CIRC 2×AT- 1 2 4
P1031 1031 A/F SEN1 HTR (B1) 2×EC-354
P1032 1032 A/F SEN1 HTR (B1) 2×EC-354
P1051 1051 A/F SEN1 HTR (B2) 2×EC-354
DTC*1
Items
(CONSULT-II screen terms)TripMIL lighting
upReference page
CONSULT-II
GST*
2ECM*3

ENGINE CONTROL SYSTEM
EC-25
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Revision: August 20072004 QX56
System ChartUBS00GZD
*1: This sensor is not used to control the engine system. This is used only for the on board diagnosis.
*2: This sensor is not used to control the engine system under normal conditions.
*3: This input signal is sent to the ECM through CAN communication line.
*4: This output signal is sent from the ECM through CAN communication line.Input (Sensor) ECM Function Output (Actuator)

Camshaft position sensor (PHASE)

Crankshaft position sensor (POS)

Mass air flow sensor

Engine coolant temperature sensor

A/F sensor 1

Throttle position sensor

Accelerator pedal position sensor

Park/neutral position (PNP) switch

Intake air temperature sensor

Power steering pressure sensor

Ignition switch

Battery voltage

Knock sensor

Refrigerant pressure sensor

Stop lamp switch

ASCD steering switch

ASCD brake switch

Fuel level sensor*1 *3

EVAP control system pressure sensor

Fuel tank temperature sensor*1

Heated oxygen sensor 2*2

TCM (Transmission control module)*3

ABS actuator and electric unit (control unit)*3

Air conditioner switch*3

Wheel sensor*3

Electrical load signal*3
Fuel injection & mixture ratio control Fuel injector
Electronic ignition system Power transistor
Nissan torque demand control system

Electric throttle control actuator

Fuel injector
Fuel pump control Fuel pump relay
ASCD vehicle speed control Electric throttle control actuator
On board diagnostic system
MIL (On the instrument panel)*
4
A/F sensor 1 heater control A/F sensor 1 heater
Heated oxygen sensor 2 heater control Heated oxygen sensor 2 heater
EVAP canister purge flow controlEVAP canister purge volume control
solenoid valve
Air conditioning cut control
Air conditioner relay*
4
Cooling fan control
Cooling fan relay*4
ON BOARD DIAGNOSIS for EVAP system EVAP canister vent control valve

EC-26Revision: August 2007
ENGINE CONTROL SYSTEM
2004 QX56
Multiport Fuel Injection (MFI) SystemUBS00GZE
INPUT/OUTPUT SIGNAL CHART
*1: This sensor is not used to control the engine system under normal conditions.
*2: This signal is sent to the ECM through CAN communication line.
*3: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the
ECM memory. The program value is preset by engine operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from both the crankshaft position sensor (POS), camshaft
position sensor (PHASE) and the mass air flow sensor.
VARIOUS FUEL INJECTION INCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compensated to improve engine performance under various operat-
ing conditions as listed below.


During warm-up

When starting the engine

During acceleration

Hot-engine operation

When selector lever is changed from N to D

High-load, high-speed operation


During deceleration

During high engine speed operation
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Engine speed*
3
Piston position
Fuel injection
& mixture ratio
controlFuel injector Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
A/F sensor 1 Density of oxygen in exhaust gas
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Park/neutral position (PNP) switch Gear position
Knock sensor Engine knocking condition
Battery
Battery voltage*
3
Power steering pressure sensor Power steering operation
Heated oxygen sensor 2*
1Density of oxygen in exhaust gas
ABS actuator and electric unit (control unit)*
2VDC/TCS operation command
Air conditioner switch*
2Air conditioner operation
Wheel sensor*
2Vehicle speed

EC-28Revision: August 2007
ENGINE CONTROL SYSTEM
2004 QX56
FUEL INJECTION TIMING
Two types of systems are used.
Sequential Multiport Fuel Injection System
Fuel is injected into each cylinder during each engine cycle according to the firing order. This system is used
when the engine is running.
Simultaneous Multiport Fuel Injection System
Fuel is injected simultaneously into all eight cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The eight injectors will then receive the signals two times for each engine cycle.
This system is used when the engine is being started and/or if the fail-safe system (CPU) is operating.
FUEL SHUT-OFF
Fuel to each cylinder is cut off during deceleration or operation of the engine at excessively high speeds.
Electronic Ignition (EI) SystemUBS00GZF
INPUT/OUTPUT SIGNAL CHART
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
The ignition timing is controlled by the ECM to maintain the best air-
fuel ratio for every running condition of the engine. The ignition tim-
ing data is stored in the ECM. This data forms the map shown.
The ECM receives information such as the injection pulse width and
camshaft position sensor signal. Computing this information, ignition
signals are transmitted to the power transistor.
e.g., N: 1,800 rpm, Tp: 1.50 msec
A °BTDC
During the following conditions, the ignition timing is revised by the
ECM according to the other data stored in the ECM.

At starting

During warm-up
PBIB0122E
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Engine speed*
2
Piston position
Ignition timing
controlPower transistor Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Knock sensor Engine knocking
Park/neutral position (PNP) switch Gear position
Battery
Battery voltage*
2
Wheel sensor*1Vehicle speed
SEF 7 42 M

ENGINE CONTROL SYSTEM
EC-29
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Revision: August 20072004 QX56

At idle

At low battery voltage

During acceleration
The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed
within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not
operate under normal driving conditions. If engine knocking occurs, the knock sensor monitors the condition.
The signal is transmitted to the ECM. The ECM retards the ignition timing to eliminate the knocking condition.
Nissan Torque Demand (NTD) Control SystemUBS00GZG
INPUT/OUTPUT SIGNAL CHART
*1: Signal is sent to the ECM through CAN communication line.
SYSTEM DESCRIPTION
NTD control system decides the target traction based on the accelerator operation status and the current driv-
ing condition. It then selects the engine torque target by correcting running resistance and atmospheric pres-
sure, and controlling the power-train. Using electric throttle control actuator, it achieves the engine torque
development target which corresponds linearly to the driver's accelerator operation.
Running resistance correction control compares the engine torque estimate value, measured vehicle acceler-
ation, and running resistance on a flat road, and estimates vehicle weight gain and running resistance varia-
tion caused by slopes to correct the engine torque estimate value.
Atmospheric pressure correction control compares the engine torque estimate value from the airflow rate and
the target engine torque for the target traction, and estimates variation of atmospheric pressure to correct the
target engine torque. This system achieves powerful driving without reducing engine performance in the prac-
tical speed range in mountains and high-altitude areas.
Sensor Input signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)Engine speed
NTD controlElectric throttle con-
trol actuator and fuel
injector Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Park/Neutral position (PNP) switch Gear position
Power steering pressure sensor Power steering operation
Battery Battery voltage
TCM (CAN communication) A/T control signal
Air conditioner switch*
1Air conditioner operation
ABS actuator and electric unit (control unit)*
1VDC/TCS/ABS operation
Wheel sensor*
1Vehicle speed
Electrical load*
1Electrical load signal

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-51
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Revision: August 20072004 QX56CYL 3 MISFIRE P0303 0303 — —×EC-243
CYL 4 MISFIRE P0304 0304 — —×EC-243
CYL 5 MISFIRE P0305 0305 — —×EC-243
CYL 6 MISFIRE P0306 0306 — —×EC-243
CYL 7 MISFIRE P0307 0307 — —×EC-243
CYL 8 MISFIRE P0308 0308 — —×EC-243
KNOCK SEN/CIRC-B1 P0327 0327 — —×EC-250
KNOCK SEN/CIRC-B1 P0328 0328 — —×EC-250
KNOCK SEN/CIRC-B2 P0332 0332 — —×EC-250
KNOCK SEN/CIRC-B2 P0333 0333 — —×EC-250
CKP SEN/CIRCUIT P0335 0335 — —×EC-255
CMP SEN/CIRC-B1 P0340 0340 — —×EC-261
TW CATALYST SYS-B1 P0420 0420×××EC-267
TW CATALYST SYS-B2 P0430 0430×××EC-267
EVAP PURG FLOW/MON P0441 0441×××EC-271
EVAP SMALL LEAK P0442 0442×××EC-276
PURG VOLUME CONT/V P0444 0444 — —×EC-285
PURG VOLUME CONT/V P0445 0445 — —×EC-285
VENT CONTROL VALVE P0447 0447 — —×EC-292
EVAP SYS PRES SEN P0451 0451 — —×EC-299
EVAP SYS PRES SEN P0452 0452 — —×EC-302
EVAP SYS PRES SEN P0453 0453 — —×EC-308
EVAP GROSS LEAK P0455 0455 —××EC-316
EVAP VERY SML LEAK P0456 0456
×*6××EC-324
FUEL LEV SEN SLOSH P0460 0460 — —×EC-334
FUEL LEVEL SENSOR P0461 0461 — —×EC-336
FUEL LEVL SEN/CIRC P0462 0462 — —×EC-338
FUEL LEVL SEN/CIRC P0463 0463 — —×EC-338
VEH SPEED SEN/CIRC*4P0500 0500 — —×EC-340
ISC SYSTEM P0506 0506 — —×EC-342
ISC SYSTEM P0507 0507 — —×EC-344
PW ST P SEN/CIRC P0550 0550 — —×EC-346
ECM P0605 0605 — —× or —EC-351
TCM P0700 0700 — — —AT- 1 0 8
PNP SW/CIRC P0705 0705 — —×AT- 1 0 9
ATF TEMP SEN/CIRC P0710 0710 — —×AT- 1 3 1
VEH SPD SEN/CIR AT*4P0720 0720 — —×AT- 11 2
TCC SOLENOID/CIRC P0740 0740 — —×AT- 11 8
A/T TCC S/V FNCTN P0744 0744 — —×AT- 1 2 1
L/PRESS SOL/CIRC P0745 0745 — —×AT- 1 2 4
A/F SEN1 HTR (B1) P1031 1031×××EC-354
A/F SEN1 HTR (B1) P1032 1032×××EC-354
Items
(CONSULT-II screen terms)DTC*
1
SRT codeTest value/
Test limit
(GST only)1st trip DTCReference
page CONSULT-II
GST*
2ECM*3

EC-76Revision: August 2007
TROUBLE DIAGNOSIS
2004 QX56
DTC Inspection Priority ChartUBS00GZX
If some DTCs are displayed at the same time, perform inspections one by one based on the following priority
chart.
NOTE:
If DTC U1000 and/or U1001 is displayed with other DTC, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-135, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
Priority Detected items (DTC)
1

U1000 U1001 CAN communication line

P0101 P0102 P0103 Mass air flow sensor

P0112 P0113 P0127 Intake air temperature sensor

P0117 P0118 P0125 Engine coolant temperature sensor

P0122 P0123 P0222 P0223 P1225 P1226 P2135 Throttle position sensor

P0128 Thermostat function

P0181 P0182 P0183 Fuel tank temperature sensor

P0327 P0328 P0332 P0333 Knock sensor

P0335 Crankshaft position sensor (POS)

P0340 Camshaft position sensor (PHASE)

P0460 P0461 P0462 P0463 Fuel level sensor

P0500 Vehicle speed sensor

P0605 ECM

P0705 Park/Neutral position (PNP) switch

P1229 Sensor power supply

P1610 - P1615 NATS

P1706 Park/Neutral position (PNP) switch

P2122 P2123 P2127 P2128 P2138 Accelerator pedal position sensor