2004 INFINITI FX35 mass air flow sensor

EC-48
[VQ35DE]
BASIC SERVICE PROCEDURE
Revision: 2004 November 2004 FX35/FX45
31. REPLACE HEATED OXYGEN SENSOR 1
1. Stop engine.
2. Replace heated oxygen sensor 1 on the malfunctioning bank.
With CONSULT-II>>GO TO 32.
Without CONSULT-II>>GO TO 33.
32. CHECK HEATED OXYGEN SENSOR 1 (BANK 1)/(BANK 2) SIGNAL
With CONSULT-II
1. Start engine and warm it up until engine coolant temperature indicator points the middle of gauge.
2. See “HO2S1 MNTR (B1)/(B2)” in “DATA MONITOR” mode.
3. Running engine at 2,000 rpm under no-load (The engine is
warmed up to normal operating temperature.), check that the
monitor fluctuates between LEAN and RICH more than 5 times
during 10 seconds.
OK or NG
OK >> GO TO 4.
NG >> GO TO 34.
33. CHECK HEATED OXYGEN SENSOR 1 (BANK 1)/(BANK 2) SIGNAL
Without CONSULT-II
1. Set ECM to Self-diagnostic mode II (Heated oxygen sensor 1 monitor). Refer to EC-70, "
HOW TO
SWITCH DIAGNOSTIC TEST MODE" .
2. Switch the monitored sensor to the malfunctioning bank. Refer to EC-70, "
How to Switch Monitored Sen-
sor From Bank 1 to Bank 2 or Vice Versa" .
3. Running engine at 2,000 rpm under no-load (The engine is warmed up to normal operating temperature.),
check that the MIL comes on more than 5 times during 10 seconds.
OK or NG
OK >> GO TO 4.
NG >> GO TO 34.
34. DETECT MALFUNCTIONING PART
Check the following.

Check fuel pressure regulator and repair or replace if necessary. Refer to EC-51, "Fuel Pressure Check" .

Check mass air flow sensor and its circuit, and repair or replace if necessary. Refer to EC-165 and EC-
173 .

Check injector and its circuit, and repair or replace if necessary. Refer to EC-597 .

Check engine coolant temperature sensor and its circuit, and repair or replace if necessary. Refer to EC-
185 and EC-197 .
OK or NG
OK >> GO TO 36.
NG >> 1. Repair or replace.
2. GO TO 35. 1 time: RICH → LEAN → RICH
2 times: RICH → LEAN → RICH → LEAN → RICH
PBIB0120E

TROUBLE DIAGNOSIS
EC-81
[VQ35DE]
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Revision: 2004 November 2004 FX35/FX45
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

P0128 Thermostat function

P0122 P0123 P0222 P0223 P1225 P1226 P2135 Throttle position sensor

P0181 P0182 P0183 Fuel tank temperature sensor

P0327 P0328 Knock sensor

P0335 Crankshaft position sensor (POS)

P0340 P0345 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
2

P0031 P0032 P0051 P0052 Heated oxygen sensor 1 heater

P0037 P0038 P0057 P0058 Heated oxygen sensor 2 heater

P0132 P0133 P0134 P0152 P0153 P0154 P1143 P1144 P1163 P1164 Heated oxygen sensor 1

P0138 P0139 P0158 P0159 P1146 P1147 P1166 P1167 Heated oxygen sensor 2

P0441 EVAP control system purge flow monitoring

P0444 P0445 P1444 EVAP canister purge volume control solenoid valve

P0447 P1446 EVAP canister vent control valve

P0451 P0452 P0453 EVAP control system pressure sensor

P0550 Power steering pressure sensor

P0710 P0720 P0725 P0740 P0744 P0745 P1705 P1716 P1730 P1752 P1754 P1757 P1759 P1762 P1764 P1767
P1769 P1772 P1774 A/T related sensors, solenoid valves and switches

P1065 ECM power supply

P 1111 P 1136 Intake valve timing control solenoid valve

P1122 Electric throttle control function

P1124 P1126 P1128 Electric throttle control actuator

P1217 Engine over temperature (OVERHEAT)

P1805 Brake switch
3

P0011 P0021 Intake valve timing control

P0171 P0172 P0174 P0175 Fuel injection system function

P0300 - P0306 Misfire

P0420 P0430 Three way catalyst function

P0442 P0455 P0456 EVAP control system

P0506 P0507 Idle speed control system

P1121 Electric throttle control actuator

P1148 P1168 Closed loop control

P1211 TCS control unit

P1212 TCS communication line

P1564 ICC steering switch/ASCD steering switch

P1568 ICC command valve

P1572 ICC brake switch/ASCD brake switch

P1574 ICC vehicle speed sensor/ASCD vehicle speed sensor

EC-82
[VQ35DE]
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
Fail-Safe ChartABS006KQ
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 MIL up 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-88
[VQ35DE]
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
Symptom Matrix ChartABS006KS
SYSTEM — BASIC ENGINE CONTROL SYSTEM
SYMPTOM
Reference
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 11232 22 3 2EC-603
Fuel pressure regulator system334444444 4EC-51
Injector circuit 11232 22 2EC-597
Evaporative emission system 334444444 4EC-643
Air Positive crankcase ventilation sys-
tem
334444444 41EC-655
Incorrect idle speed adjustment 1 1 1 1 1EC-38
Electric throttle control actuator 112332222 2 2EC-415,
EC-417
IgnitionIncorrect ignition timing adjustment33111 11 1EC-38
Ignition circuit 11222 22 2EC-585
Power supply and ground circuit22333 33 23EC-136
Mass air flow sensor circuit
1
122
222 2EC-165,
EC-173
Engine coolant temperature sensor circuit
333EC-185,
EC-197
Heated oxygen sensor 1 circuitEC-205
,
EC-214
,
EC-226
,
EC-433
,
EC-439
Throttle position sensor circuit
22EC-190
,
EC-284
,
EC-485
,
EC-487
,
EC-569
Accelerator pedal position sensor circuit 3 2 1EC-489
,
EC-555
,
EC-562
,
EC-576
Knock sensor circuit 2 3EC-297
Crankshaft position sensor (POS) circuit 2 2EC-302
Camshaft position sensor (PHASE) circuit 3 2EC-308
Vehicle speed signal circuit 2 3 3 3EC-390
Power steering pressure sensor circuit 2 3 3EC-396

EC-90
[VQ35DE]
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
Air Air duct
55555 5EM-17
Air cleanerEM-17
Air leakage from air duct
(Mass air flow sensor — electric
throttle control actuator)
5555EM-17
Electric throttle control actuatorEM-19
Air leakage from intake manifold/
Collector/GasketEM-19,
EM-24
Cranking Battery
111111
11SC-4
Generator circuitSC-23
Starter circuit 3SC-10
Signal plate 6EM-120
PNP switch 4AT- 11 2
Engine Cylinder head
55555 55 5EM-98
Cylinder head gasket 4 3
Cylinder block
66666 66 64
EM-120
Piston
Piston ring
Connecting rod
Bearing
Crankshaft
Va l v e
mecha-
nismTiming chain
55555 55 5EM-63
CamshaftEM-82
Intake valve timing controlEM-63
Intake valve
3EM-98
Exhaust valve
Exhaust Exhaust manifold/Tube/Muffler/
Gasket
55555 55 5EM-26
, EX-
3Three way catalyst
Lubrica-
tionOil pan/Oil strainer/Oil pump/Oil
filter/Oil gallery/Oil cooler
55555 55 5EM-30
, LU-
17 , LU-10 ,
LU-14
Oil level (Low)/Filthy oilLU-7
SYMPTOM
Reference
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

TROUBLE DIAGNOSIS
EC-105
[VQ35DE]
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Revision: 2004 November 2004 FX35/FX45
45 GYEVAP canister purge vol-
ume control solenoid valve[Engine is running]

Idle speedBATTERY VOLTAGE
(11 - 14V)
[Engine is running]

Engine speed is about 2,000 rpm (More
than 100 seconds after starting engine)BATTERY VOLTAGE
(11 - 14V)
47 LSensor power supply
(Throttle position sensor)[Ignition switch: ON]Approximately 5V
48 LGSensor power supply
(EVAP control system pres-
sure sensor)[Ignition switch: ON]Approximately 5V
49 PUSensor power supply
(Refrigerant pressure sen-
sor)[Ignition switch: ON]Approximately 5V
50 W Throttle position sensor 1[Ignition switch: ON]

Engine stopped

Shift lever: D

Accelerator pedal: Fully releasedMore than 0.36V
[Ignition switch: ON]

Engine stopped

Shift lever: D

Accelerator pedal: Fully depressedLess than 4.75V
51 L/W Mass air flow sensor[Engine is running]

Warm-up condition

Idle speed0.9 - 1.2V
[Engine is running]

Warm-up condition

Engine speed is 2,500 rpm1.6 - 1.9V
55 W/RHeated oxygen sensor 2
(bank 2)[Engine is running]

Warm-up condition

Revving engine from idle to 3,000 rpm
quickly after the following conditions are met
–After keeping the engine speed between
3,500 and 4,000 rpm for 1 minute and at idle
for 1 minute under no load0 - Approximately 1.0V TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
SEC990C
SEC991C

EC-110
[VQ35DE]
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45

Te s t v a l u e s

Others
ENGINE CONTROL COMPONENT PARTS/CONTROL SYSTEMS APPLICATION
ItemDIAGNOSTIC TEST MODE
WORK
SUP-
PORTSELF-DIAGNOSTIC
RESULTS
DATA
MONI-
TORDATA
MONI-
TOR
(SPEC)ACTIVE
TESTDTC & SRT
CONFIRMATION
DTC*1FREEZE
FRAME
DATA*2SRT
STATUSDTC
WORK
SUP-
PORT
ENGINE CONTROL COMPONENT PARTS
INPUT
Crankshaft position sensor (POS)××××
Camshaft position sensor (PHASE)××××
Mass air flow sensor×××
Engine coolant temperature sensor×××××
Heated oxygen sensor 1×××××
Heated oxygen sensor 2×××××
Vehicle speed sensor××××
Accelerator pedal position sensor×××
Throttle position sensor×××
Fuel tank temperature sensor××××
EVAP control system pressure
sensor×××
Intake air temperature sensor××××
Knock sensor×
Refrigerant pressure sensor××
Closed throttle position switch
(accelerator pedal position sensor
signal)××
Air conditioner switch××
Park/neutral position (PNP) switch×××
Stop lamp switch×××
Power steering pressure sensor×××
Battery voltage××
Load signal××
Fuel level sensor×××
ICC steering switch×××
ASCD steering switch×××
ICC brake switch×××
ASCD brake switch×××
Snow mode switch××

EC-114
[VQ35DE]
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
DATA MONITOR MODE
Monitored Item
×: Applicable
Monitored item [Unit]ECM
INPUT
SIG-
NALSMAIN
SIG-
NALSDescription Remarks
ENG SPEED [rpm]××

Indicates the engine speed computed from
the signal of the crankshaft position sensor
(POS) and camshaft position sensor
(PHASE).
Accuracy becomes poor if engine
speed drops below the idle rpm.

If the signal is interrupted while the
engine is running, an abnormal value
may be indicated.
MAS A/F SE-B1 [V]××

The signal voltage of the mass air flow sen-
sor is displayed.
When the engine is stopped, a cer-
tain value is indicated.
B/FUEL SCHDL
[msec]×

Base fuel schedule indicates the fuel injec-
tion pulse width programmed into ECM,
prior to any learned on board correction.
A/F ALPHA-B1 [%]×

The mean value of the air-fuel ratio feed-
back correction factor per cycle is indicated.

When the engine is stopped, a cer-
tain value is indicated.

This data also includes the data for
the air-fuel ratio learning control. A/F ALPHA-B2 [%]×
COOLAN TEMP/S
[°C] or [°F]××

The engine coolant temperature (deter-
mined by the signal voltage of the engine
coolant temperature sensor) is displayed.

When the engine coolant tempera-
ture sensor is open or short-circuited,
ECM enters fail-safe mode. The
engine coolant temperature deter-
mined by the ECM is displayed.
HO2S1 (B1) [V]××

The signal voltage of the heated oxygen
sensor 1 is displayed.
HO2S1 (B2) [V]×
HO2S2 (B1) [V]×

The signal voltage of the heated oxygen
sensor 2 is displayed.
HO2S2 (B2) [V]×
HO2S1 MNTR (B1)
[RICH/LEAN]××

Display of heated oxygen sensor 1 signal
during air-fuel ratio feedback control:
RICH: means the mixture became rich, and
control is being affected toward a leaner
mixture.
LEAN: means the mixture became lean,
and control is being affected toward a rich
mixture.
After turning ON the ignition switch,
RICH is displayed until air-fuel mix-
ture ratio feedback control begins.

When the air-fuel ratio feedback is
clamped, the value just before the
clamping is displayed continuously. HO2S1 MNTR (B2)
[RICH/LEAN]×
HO2S2 MNTR (B1)
[RICH/LEAN]×

Display of heated oxygen sensor 2 signal:
RICH: means the amount of oxygen after
three way catalyst is relatively small.
LEAN: means the amount of oxygen after
three way catalyst is relatively large.

When the engine is stopped, a cer-
tain value is indicated.
HO2S2 MNTR (B2)
[RICH/LEAN]×
VHCL SPEED SE
[km/h] or [mph]××

The vehicle speed computed from the vehi-
cle speed signal sent from combination
meter is displayed.
BATTERY VOLT [V]××

The power supply voltage of ECM is dis-
played.
ACCEL SEN 1 [V]××

The accelerator pedal position sensor sig-
nal voltage is displayed.
ACCEL SEN2 signal is converted by
ECM internally. Thus, they differs
from ECM terminal voltage signal. ACCEL SEN 2 [V]×
THRTL SEN 1 [V]××

The throttle position sensor signal voltage
is displayed.
THRTL SEN2 signal is converted by
ECM internally. Thus, they differs
from ECM terminal voltage signal. THRTL SEN 2 [V]×