2007 INFINITI M35 Mass air flow

EC-510
[VQ35DE]
DTC P1220 FUEL PUMP CONTROL MODULE (FPCM)
Revision: 2007 April2007 M35/M45
DTC P1220 FUEL PUMP CONTROL MODULE (FPCM)PFP:17001
DescriptionNBS0053A
SYSTEM DESCRIPTION
*: ECM determines the start signal status by the signals of engine speed and battery voltage.
This system controls the fuel pump operation. The amount of fuel flow delivered from the fuel pump is altered
between two flow rates by the FPCM operation. The FPCM determines the voltage supplied to the fuel pump
(and therefore fuel flow) according to the following conditions.
COMPONENT DESCRIPTION
The FPCM adjusts the voltage supplied to the fuel pump to control
the amount of fuel flow. When the FPCM increases the voltage sup-
plied to the fuel pump, the fuel flow is increased. When the FPCM
decreases the voltage, the fuel flow is decreased.
CONSULT-II Reference Value in Data Monitor ModeNBS0053B
Specification data are reference values.
On Board Diagnosis LogicNBS0053C
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed*
Fuel pump controlFuel pump control module
(FPCM) Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Battery Battery voltage*
Conditions Amount of fuel flow Supplied voltage

Engine cranking

Engine coolant temperature is below 10°C (50°F).

Engine is running under heavy load and high speed conditionshighBattery voltage
(11 - 14V)
Except the above low Approximately 8V
SEF387X
MONITOR ITEM CONDITION SPECIFICATION
FPCM

Engine: Cranking HI

Engine: Idle

Engine coolant temperature: More than 10°C (50°F)LOW
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1220
1220Fuel pump control module
(FPCM)An improper voltage signal from the FPCM, which
is supplied to a point between the fuel pump and
the dropping resistor, is detected by ECM.

Harness or connectors
(FPCM circuit is shorted.)

Dropping resistor

FPCM

DTC P2A00, P2A03 A/F SENSOR 1
EC-647
[VQ35DE]
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Revision: 2007 April2007 M35/M45
4. Clear the self-learning coefficient by touching “CLEAR”.
5. Turn ignition switch OFF and wait at least 10 seconds.
6. Start engine and keep the engine speed between 3,500 and
4,000 rpm for 1 minute under no load.
7. Let engine idle for 1 minute.
8. Keep engine speed between 2,500 and 3,000 rpm for 20 min-
utes.
9. If 1st trip DTC is detected, go to EC-651, "
Diagnostic Procedure"
.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Disconnect mass air flow sensor (1) harness connector.
4. Start engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con-
nector.
6. Select Service $03 with GST and make sure that DTC P0102 is
detected.
7. Select Service $04 with GST and erase the DTC P0102.
8. Start engine and keep the engine speed between 3,500 and
4,000 rpm for 1 minute under no load.
9. Let engine idle for 1 minute.
10. Keep engine speed between 2,500 and 3,000 rpm for 20 min-
utes.
11. Select Service $07 with GST.
If 1st trip DTC is detected, go to EC-651, "
Diagnostic Procedure" .
SEF968Y
PBIB2783E

EC-652
[VQ35DE]
DTC P2A00, P2A03 A/F SENSOR 1
Revision: 2007 April2007 M35/M45
2. RETIGHTEN A/F SENSOR 1
1. Loosen and retighten the A/F sensor 1.
>> GO TO 3.
3. CHECK FOR INTAKE AIR LEAK
1. Start engine and run it at idle.
2. Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.Tightening torque: 50 N-m (5.1 kg-m, 37 ft-lb)
PBIB2200E

DTC P2A00, P2A03 A/F SENSOR 1
EC-653
[VQ35DE]
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Revision: 2007 April2007 M35/M45
4. CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching “CLEAR”.
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor (1) harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con-
nector.
6. Make sure DTC P0102 is displayed.
7. Erase the DTC memory. Refer to EC-68, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
8. Make sure DTC P0000 is displayed.
9. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Ye s o r N o
Yes >> Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to EC-309, "DTC
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION" or EC-320, "DTC P0172, P0175 FUEL
INJECTION SYSTEM FUNCTION" .
No >> GO TO 5.
SEF968Y
PBIB2783E

EC-716
[VQ35DE]
SERVICE DATA AND SPECIFICATIONS (SDS)
Revision: 2007 April2007 M35/M45
SERVICE DATA AND SPECIFICATIONS (SDS)PFP:00030
Fuel PressureNBS0058W
Idle Speed and Ignition TimingNBS0058X
*: Under the following conditions:

Air conditioner switch: OFF

Electric load: OFF (Lights, heater fan & rear window defogger)

Steering wheel: Kept in straight-ahead position
Calculated Load ValueNBS0058Y
Mass Air Flow SensorNBS0058Z
*: Engine is warmed up to normal operating temperature and running under no load.
Intake Air Temperature SensorNBS00590
Engine Coolant Temperature SensorNBS00591
Fuel Tank Temperature SensorNBS00592
Crankshaft Position Sensor (POS)NBS00593
Refer to EC-370, "Component Inspection" .
Camshaft Position Sensor (PHASE)NBS00594
Refer to EC-379, "Component Inspection" .
A/F Sensor 1 HeaterNBS00595
Fuel pressure at idling kPa (kg/cm2 , psi)Approximately 350 (3.57, 51)
Target idle speed No load* (in P or N position) 650 ± 50 rpm
Air conditioner: ON In P or N position 700 rpm or more
Ignition timing In P or N position 15° ± 5° BTDC
Condition Calculated load value% (Using CONSULT-II or GST)
At idle5.0 - 35.0
At 2,500 rpm5.0 - 35.0
Supply voltageBattery voltage (11 - 14V)
Output voltage at idle0.9 - 1.2V*
Mass air flow (Using CONSULT-II or GST)2.0 - 6.0 g·m/sec at idle*
7.0 - 20.0 g·m/sec at 2,500 rpm*
Temperature °C (°F) Resistance kΩ
25 (77)1.800 - 2.200
80 (176)0.283 - 0.359
Temperature °C (°F) Resistance kΩ
20 (68)2.1 - 2.9
50 (122)0.68 - 1.00
90 (194)0.236 - 0.260
Temperature °C (°F) Resistance kΩ
20 (68)2.3 - 2.7
50 (122)0.79 - 0.90
Resistance [at 25°C (77°F)] 2.3 - 4.3Ω

EC-728
[VK45DE]
PRECAUTIONS
Revision: 2007 April2007 M35/M45

Before replacing ECM, perform ECM Terminals and Refer-
ence Value inspection and make sure ECM functions prop-
erly. Refer to EC-817, "
ECM Terminals and Reference Value"
.

Handle mass air flow sensor carefully to avoid damage.

Do not clean mass air flow sensor with any type of deter-
gent.

Do not disassemble electric throttle control actuator.

Even a slight leak in the air intake system can cause seri-
ous incidents.

Do not shock or jar the camshaft position sensor (PHASE),
crankshaft position sensor (POS).

After performing each TROUBLE DIAGNOSIS, perform DTC
Confirmation Procedure or Overall Function Check.
The DTC should not be displayed in the DTC Confirmation
Procedure if the repair is completed. The Overall Function
Check should be a good result if the repair is completed.

When measuring ECM signals with a circuit tester, never
allow the two tester probes to contact.
Accidental contact of probes will cause a short circuit and
damage the ECM power transistor.

Do not use ECM ground terminals when measuring input/
output voltage. Doing so may result in damage to the ECM's
transistor. Use a ground other than ECM terminals, such as
the ground.
MEF040D
SEF217U
SEF348N

ENGINE CONTROL SYSTEM
EC-733
[VK45DE]
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Revision: 2007 April2007 M35/M45
Multiport Fuel Injection (MFI) SystemNBS0059J
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 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
Air fuel ratio (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
Battery
Battery voltage*
3
Knock sensor Engine knocking condition
Power steering pressure sensor Power steering operation
Heated oxygen sensor 2*
1Density of oxygen in exhaust gas
ABS actuator and electric unit (control unit)
VDC/TCS operation command*
2
Air conditioner switch
Air conditioner operation*2
Wheel sensor
Vehicle speed*2

EC-734
[VK45DE]
ENGINE CONTROL SYSTEM
Revision: 2007 April2007 M35/M45
MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
The mixture ratio feedback system provides the best air-fuel mixture ratio for driveability and emission control.
The three way catalyst (manifold) can then better reduce CO, HC and NOx emissions. This system uses A/F
sensor 1 in the exhaust manifold to monitor whether the engine operation is rich or lean. The ECM adjusts the
injection pulse width according to the sensor voltage signal. For more information about A/F sensor 1, refer to
EC-947, "
DTC P0130, P0150 A/F SENSOR 1" . This maintains the mixture ratio within the range of stoichio-
metric (ideal air-fuel mixture).
This stage is referred to as the closed loop control condition.
Heated oxygen sensor 2 is located downstream of the three way catalyst (manifold). Even if the switching
characteristics of A/F sensor 1 shift, the air-fuel ratio is controlled to stoichiometric by the signal from heated
oxygen sensor 2.
Open Loop Control
The open loop system condition refers to when the ECM detects any of the following conditions. Feedback
control stops in order to maintain stabilized fuel combustion.

Deceleration and acceleration

High-load, high-speed operation

Malfunction of A/F sensor 1 or its circuit

Insufficient activation of A/F sensor 1 at low engine coolant temperature

High engine coolant temperature

During warm-up

After shifting from N to D

When starting the engine
MIXTURE RATIO SELF-LEARNING CONTROL
The mixture ratio feedback control system monitors the mixture ratio signal transmitted from A/F sensor 1.
This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio as close to the theoret-
ical mixture ratio as possible. However, the basic mixture ratio is not necessarily controlled as originally
designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic changes dur-
ing operation (i.e., fuel injector clogging) directly affect mixture ratio.
Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This is
then computed in terms of “injection pulse duration” to automatically compensate for the difference between
the two ratios.
“Fuel trim” refers to the feedback compensation value compared against the basic injection duration. Fuel trim
includes short term fuel trim and long term fuel trim.
“Short term fuel trim” is the short-term fuel compensation used to maintain the mixture ratio at its theoretical
value. The signal from A/F sensor 1 indicates whether the mixture ratio is RICH or LEAN compared to the the-
oretical value. The signal then triggers a reduction in fuel volume if the mixture ratio is rich, and an increase in
fuel volume if it is lean.
“Long term fuel trim” is overall fuel compensation carried out long-term to compensate for continual deviation
of the short term fuel trim from the central value. Such deviation will occur due to individual engine differences,
wear over time and changes in the usage environment.
PBIB3020E