P0171 NISSAN ALMERA N16 2003 Electronic User Guide

EC-188
[QG (WITH EURO-OBD)]
DTC P0171 FUEL INJECTION SYSTEM FUNCTION
Wiring Diagram
EBS00K6S
YEC285A

DTC P0171 FUEL INJECTION SYSTEM FUNCTION
EC-189
[QG (WITH EURO-OBD)]
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Diagnostic ProcedureEBS00K6T
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 AND PCV HOSE
1. Listen for an intake air leak after the mass air flow sensor.
2. Check PCV hose connection.
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.
SEC502D
Continuity should exist.
Continuity should not exist.
MBIB0091E

EC-190
[QG (WITH EURO-OBD)]
DTC P0171 FUEL INJECTION SYSTEM FUNCTION
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”.
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" . At idling: Approximately 350 kPa (3.5 bar, 3.57 kg/cm
2 , 51 psi)
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

DTC P0171 FUEL INJECTION SYSTEM FUNCTION
EC-191
[QG (WITH EURO-OBD)]
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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" .
7.CHECK INJECTOR
1. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
2. Turn ignition switch “OFF”.
3. Disconnect injector harness connectors.
4. Remove injector gallery assembly. Refer to EM-26, "
FUEL INJECTOR AND FUEL TUBE" .
Keep fuel hose and all injectors connected to injector gallery.
The injector harness connectors should remain connected.
5. Disconnect all ignition coil harness connectors.
6. Prepare pans or saucers under each injector.
7. Crank engine for about 3 seconds. Make sure that fuel sprays
out from injectors.
OK or NG
OK >> GO TO 8.
NG >> Replace injectors from which fuel does not spray out.
Always replace O-ring with new ones.
PBIB0133E
Clicking noise should be heard.
MEC703B
Fuel should be sprayed evenly for each injector.
SEF595Q

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 P1143 HO2S1
EC-299
[QG (WITH EURO-OBD)]
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3.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 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 harness connector, and 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. Make sure that DTC P0102 is displayed.
6. Erase the DTC memory. Refer to EC-48, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
7. Make sure that DTC P0000 is displayed.
8. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 detected?
Is it difficult to start engine?
Ye s o r N o
Yes >> Perform trouble diagnosis for DTC P0171. Refer to EC-186 .
No >> GO TO 4.
4.CHECK HEATED OXYGEN SENSOR 1 HEATER
Refer to EC-127, "
Component Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Replace heated oxygen sensor 1.
5.CHECK HEATED OXYGEN SENSOR 1
Refer to EC-300, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace heated oxygen sensor 1.
6.CHECK INTERMITTENT INCIDENT
Refer to EC-109, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
For circuit, refer to EC-151, "
Wiring Diagram" .
>>INSPECTION END
SEF215Z
MBIB0096E

DTC P1147 HO2S2
EC-321
[QG (WITH EURO-OBD)]
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2.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 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 harness connector, and 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. Make sure that DTC P0102 is displayed.
6. Erase the DTC memory. Refer to EC-48, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
7. Make sure that DTC P0000 is displayed.
8. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 detected?
Is it difficult to start engine?
Ye s o r N o
Yes >> Perform trouble diagnosis for DTC P0171. Refer to EC-186 .
No >> GO TO 3.
3.CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch “OFF”.
2. Disconnect heated oxygen sensor 2 harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between ECM terminal 74 and HO2S2
terminal 3.
Refer to Wiring Diagram.
5. Also check harness for short to ground and 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.
SEF215Z
MBIB0096E
Continuity should exist.
MBIB0256E

AT-38
[EURO-OBD]
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
A sample of CONSULT-II display for DTC is shown in the following
page. DTC or 1st trip DTC of a malfunction is displayed in SELF
DIAGNOSIS mode for “ENGINE” with CONSULT-II. Time data indi-
cates how many times the vehicle was driven after the last detection
of a DTC.
If the DTC is being detected currently, the time data will be “0”.
If a 1st trip DTC is stored in the ECM, the time data will be “1t”.
Freeze Frame Data and 1st Trip Freeze Frame Data
The ECM has a memory function, which stores the driving condition such as fuel system status, calculated
load value, engine coolant temperature, short term fuel trim, long term fuel trim, engine speed and vehicle
speed at the moment the ECM detects a malfunction.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data,
and the data, stored together with the DTC data, are called freeze frame data and displayed on CONSULT-II
or GST. The 1st trip freeze frame data can only be displayed on the CONSULT-II screen, not on the GST. For
detail, refer to EC-87, "
CONSULT-II Function" (QG).
Only one set of freeze frame data (either 1st trip freeze frame data of freeze frame data) can be stored in the
ECM. 1st trip freeze frame data is stored in the ECM memory along with the 1st trip DTC. There is no priority
for 1st trip freeze frame data and it is updated each time a different 1st trip DTC is detected. However, once
freeze frame data (2nd trip detection/MI on) is stored in the ECM memory, 1st trip freeze frame data is no
longer stored. Remember, only one set of freeze frame data can be stored in the ECM.
The ECM has the following priorities to update the data.
Both 1st trip freeze frame data and freeze frame data (along with the DTCs) are cleared when the ECM mem-
ory is erased.
SAT014K
SAT015K
SAT016K
Priority Items
1 Freeze frame data Misfire — DTC: P0300 - P0306
Fuel Injection System Function — DTC: P0171, P0172, P0174, P0175
2 Except the above items (Includes A/T related items)
3 1st trip freeze frame data