2003 NISSAN ALMERA N16 fuel

EC-192
[QG (WITH EURO-OBD)]
DTC P0171 FUEL INJECTION SYSTEM FUNCTION
8. CHECK INTERMITTENT INCIDENT
Refer to EC-109, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END

DTC P0172 FUEL INJECTION SYSTEM FUNCTION
EC-193
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DTC P0172 FUEL INJECTION SYSTEM FUNCTIONPFP:16600
On Board Diagnosis LogicEBS00K6U
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. The
ECM calculates the necessary compensation to correct the offset between the actual and the theoretical
ratios.
In case the amount of the compensation value is extremely large (The actual mixture ratio is too rich.), the
ECM judges the condition as the fuel injection system malfunction and light up the MI (2 trip detection logic).
DTC Confirmation ProcedureEBS00K6V
NOTE:
If “DTC Confirmation Procedure” has been previously conducted, always turn ignition switch “OFF” and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch “OFF” and wait at least 10 seconds.
3. Turn ignition switch “ON” and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON-
SULT-II.
4. Clear the self-learning control coefficient by touching “CLEAR”.
5. Select “DATA MONITOR” mode with CONSULT-II.
6. Start engine again and let it idle for at least 10 minutes.
The 1st trip DTC P0172 should be detected at this stage, if a
malfunction exists. If so, go to EC-196, "
Diagnostic Procedure" .
7. If it is difficult to start engine at step 6, the fuel injection system
has a malfunction, too.
8. Crank engine while depressing accelerator pedal.
If engine starts, go to EC-196, "
Diagnostic Procedure" . If engine
does not start, remove ignition plugs and check for fouling, etc.
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 harness connector. Then
restart and run engine for at least 5 seconds at idle speed.
4. Stop engine and reconnect mass air flow sensor harness con-
nector.
5. Select “MODE 3” with GST. Make sure DTC P0102 is detected.
6. Select “MODE 4” with GST and erase the DTC P0102.
7. Start engine again and let it idle for at least 10 minutes.
8. Select “MODE 7” with GST. The 1st trip DTC P0172 should be
detected at this stage, if a malfunction exists. If so, go to EC-
196, "Diagnostic Procedure" .
Sensor Input Signal to ECM ECM function Actuator
Heated oxygen sensors 1Density of oxygen in exhaust gas
(Mixture ratio feedback signal)Fuel injection control Fuel injectors
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0172
0172Fuel injection system too
rich
●Fuel injection system does not operate properly.
●The amount of mixture ratio compensation is too
large.
(The mixture ratio is too rich.)
●Heated oxygen sensor 1
●Injectors
●Exhaust gas leaks
●Incorrect fuel pressure
●Mass air flow sensor
SEF215Z
MBIB0096E

EC-194
[QG (WITH EURO-OBD)]
DTC P0172 FUEL INJECTION SYSTEM FUNCTION
9. If it is difficult to start engine at step 7, the fuel injection system has a malfunction.
10. Crank engine while depressing accelerator pedal.
If engine starts, go to EC-196, "
Diagnostic Procedure" . If engine does not start, check exhaust and intake
air leak visually.

DTC P0172 FUEL INJECTION SYSTEM FUNCTION
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Wiring DiagramEBS00K6W
YEC285A

EC-196
[QG (WITH EURO-OBD)]
DTC P0172 FUEL INJECTION SYSTEM FUNCTION
Diagnostic Procedure
EBS00K6X
1. CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst (manifold).
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2. CHECK FOR INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3. CHECK HEATED OXYGEN SENSOR 1 CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch “OFF”.
2. Disconnect heated oxygen sensor 1 (HO2S1) harness connec-
tor.
3. Disconnect ECM harness connector.
4. Check harness continuity between ECM terminal 35 and HO2S1
terminal 2, ECM terminal 74 and HO2S1 terminal 3.
Refer to Wiring Diagram.
5. Check harness continuity between ECM terminals 35 or HO2S1
terminals 2 and ground.
Refer to Wiring Diagram.
6. Also check harness for short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK FUEL PRESSURE
1. Release fuel pressure to zero. Refer to EC-34, "
FUEL PRESSURE RELEASE" .
2. Install fuel pressure gauge and check fuel pressure. Refer to EC-34, "
FUEL PRESSURE CHECK" .
OK or NG
OK >> GO TO 5.
NG >> Follow the construction of “FUEL PRESSURE CHECK”.
SEC502D
Continuity should exist.
Continuity should not exist.
MBIB0091E
At idling: 350 kPa (3.5 bar, 3.57 kg/cm2, 51 psi)

DTC P0172 FUEL INJECTION SYSTEM FUNCTION
EC-197
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5.CHECK MASS AIR FLOW SENSOR
With CONSULT-II
1. Install all removed parts.
2. Check “MASS AIR FLOW” in “DATA MONITOR” mode with CONSULT-II.
With GST
1. Install all removed parts.
2. Check mass air flow sensor signal in MODE 1 with GST.
OK or NG
OK >> GO TO 6.
NG >> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or
engine grounds. Refer to EC-134, "
DTC P0102, P0103 MAF SENSOR" .
6.CHECK FUNCTION OF INJECTORS
With CONSULT-II
1. Start engine.
2. Perform “POWER BALANCE” in “ACTIVE TEST” mode with
CONSULT-II.
3. Make sure that each circuit produces a momentary engine
speed drop.
Without CONSULT-II
1. Start engine.
2. Listen to each injector operating sound.
OK or NG
OK >> GO TO 7.
NG >> Perform trouble diagnosis for EC-375, "
INJECTOR CIRCUIT" . 1.0 - 4.0 g·m/sec: at idling
5.0 - 10 g·m/sec: at 2,500 rpm
1.0 - 4.0 g·m/sec: at idling
5.0 - 10 g·m/sec: at 2,500 rpm
PBIB0133E
Clicking noise should be heard.
MEC703B

EC-198
[QG (WITH EURO-OBD)]
DTC P0172 FUEL INJECTION SYSTEM FUNCTION
7. CHECK INJECTOR
1. Remove injector assembly. Refer to EM-26, "
FUEL INJECTOR AND FUEL TUBE" .
Keep fuel hose and all injectors connected to injector gallery.
2. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
3. Disconnect injector harness connectors.
The injector harness connectors should remain connected.
4. Disconnect all ignition coil harness connectors.
5. Prepare pans or saucers under each injectors.
6. Crank engine for about 3 seconds.
Make sure fuel does not drip from injector.
OK or NG
OK (Does not drip.)>>GO TO 8.
NG (Drips.)>>Replace the injectors from which fuel is dripping. Always replace O-ring with new one.
8. CHECK INTERMITTENT INCIDENT
Refer to EC-109, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END

DTC P0226 APP SENSOR
EC-211
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DTC P0226 APP SENSORPFP:18002
Component DescriptionEBS00K7E
The accelerator pedal position sensor is installed on the upper end
of the accelerator pedal assembly. The sensor detects the accelera-
tor position and sends a signal to the ECM.
Accelerator pedal position sensor has two sensors. These sensors
are a kind of potentiometers which transform the accelerator pedal
position into output voltage, and emit the voltage signal to the ECM.
In addition, these sensors detect the opening and closing speed of
the accelerator pedal and feed the voltage signals to the ECM. The
ECM judges the current opening angle of the accelerator pedal from
these signals and controls the throttle control motor based on these
signals.
Idle position of the accelerator pedal is determined by the ECM
receiving the signal from the accelerator pedal position sensor. The ECM uses this signal for the engine oper-
ation such as fuel cut.
CONSULT-II Reference Value in Data Monitor ModeEBS00K7F
Specification data are reference values.
*: Accelerator pedal position sensor 2 signal is converted by ECM internally. Thus, it differs from ECM terminal voltage signal.
On Board Diagnosis LogicEBS00K7G
This self-diagnosis has the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode and the MI lights up.
DTC Confirmation ProcedureEBS00K7H
NOTE:
If “DTC Confirmation Procedure” has been previously conducted, always turn ignition switch “OFF” and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10V at idle.
PBIB0146E
MONITOR ITEM CONDITION SPECIFICATION
ACCEL SEN1
ACCEL SEN2*
●Ignition switch: ON
(engine stopped)Accelerator pedal: Fully released 0.35 - 0.67V
Accelerator pedal: Fully depressed More than 3.9V
CLSD THL POS
●Ignition switch: ONAccelerator pedal: Fully released ON
Accelerator pedal: Slightly depressed OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0226
0226Accelerator pedal position sensor
circuit range/performance problemRationally incorrect voltage is sent to ECM
compared with the signals from APP sensor
1 and APP sensor 2.
●Harness or connector
(The APP sensor 1 and 2 circuit is
open or shorted.)
●Accelerator pedal position sensor 1
and 2
Engine operating condition in fail-safe mode
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 throttle valve to be slower than the normal condition.
So, the acceleration will be poor.