2001 NISSAN ALMERA ignition

7 CHECK FUNCTION OF INJECTORS
With CONSULT-II
1. Install all parts removed.
2. Start engine.
3. Perform ªPOWER BALANCEº in ªACTIVE TESTº mode with CONSULT-II.
SEF190Y
4. Make sure that each circuit produces a momentary engine speed drop.
Without CONSULT-II
1. Install all parts removed.
2. Start engine.
3. Listen to each injector operating sound.
MEC703B
Clicking noise should be heard.
OK or NG
OK©GO TO 8.
NG©Perform trouble diagnosis for ªINJECTORSº, EC-541.
8 REMOVE INJECTOR
1. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
2. Turn ignition switch ªOFFº.
3. Remove injector with fuel tube assembly. Refer to EC-41.
Keep fuel hose and all injectors connected to injector gallery. The injector harness connectors should remain con-
nected.
©GO TO 9.
DTC P0171 FUEL INJECTION SYSTEM FUNCTION (LEAN SIDE)QG
Diagnostic Procedure (Cont'd)
EC-303

9 CHECK INJECTOR
1. Disconnect all ignition coil harness connectors.
2. Place pans or saucers under each injector.
3. Crank engine for about 3 seconds. Make sure that fuel sprays out from injectors.
SEF595Q
Fuel should be sprayed evenly for each cylinder.
OK or NG
OK©GO TO 10.
NG©Replace injectors from which fuel does not spray out. Always replace O-ring with new
one.
10 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-177.
©INSPECTION END
DTC P0171 FUEL INJECTION SYSTEM FUNCTION (LEAN SIDE)QG
Diagnostic Procedure (Cont'd)
EC-304

On Board Diagnosis LogicNJEC0192With 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 sensor 1 (front).
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 lights up the MIL (2 trip detection logic).
Sensor Input Signal to ECMECM func-
tionActuator
Heated oxygen sensor 1 (front)Density of oxygen in exhaust gas
(Mixture ratio feedback signal)Fuel injec-
tion & mix-
ture ratio
controlInjectors
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0172
0172+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 (front)
+Injectors
+Exhaust gas leaks
+Incorrect fuel pressure
+Mass air flow sensor
SEF215Z
SEF058Y
DTC Confirmation ProcedureNJEC0193NOTE:
If ªDTC Confirmation Procedure º has been previously conducted,
always turn ignition switch ªOFFº and wait at least 9 seconds
before conducting the next test.
With CONSULT-II
1) Start engine and warm it up to normal operating temperature.
2) Turn ignition switch ªOFFº and wait at least 9 seconds.
3) Turn ignition switch ªONº and select ªSELF-LEARN CON-
TROLº in ªWORK SUPPORTº mode with CONSULT-II.
4) Clear the self-learning control coefficient by touching ªSTARTº.
5) Select ªDATA MONITORº 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 ªDiagnostic Procedureº,
EC-309.
7) If it is difficult to start engine at step 6, the fuel injection sys-
tem has a malfunction.
8) Crank engine while depressing accelerator pedal. If engine
starts, go to ªDiagnostic Procedureº, EC-309. If engine does
not start, remove ignition plugs and check for fouling, etc.
JEF105Y
With GST
1) Start engine and warm it up to normal operating temperature.
2) Turn ignition switch ªOFFº and wait at least 9 seconds.
3) Disconnect mass air flow sensor harness connector. Then
restart and run engine for at least 3 seconds at idle speed.
4) Stop engine and reconnect mass air flow sensor harness con-
nector.
5) Select ªMODE 7º with GST. Make sure 1st trip DTC P0100 is
detected.
6) Select ªMODE 4º with GST and erase the 1st trip DTC P0100.
DTC P0172 FUEL INJECTION SYSTEM FUNCTION (RICH SIDE)QG
On Board Diagnosis Logic
EC-305

7) Start engine again and run it for at least 10 minutes at idle
speed.
8) Select ªMODE 7º with GST. The 1st trip DTC P0172 should be
detected at this stage, if a malfunction exists. If so, go to
ªDiagnostic Procedureº, EC-309.
9) If it is difficult to start engine at step 8, the fuel injection sys-
tem has a malfunction.
10) Crank engine while depressing accelerator pedal.
If engine starts, go to ªDiagnostic Procedureº, EC-309. If
engine does not start, remove ignition plugs and check for
fouling, etc.
DTC P0172 FUEL INJECTION SYSTEM FUNCTION (RICH SIDE)QG
DTC Confirmation Procedure (Cont'd)
EC-306

Diagnostic ProcedureNJEC0195
1 CHECK FOR EXHAUST AIR LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust air leak before the three way catalyst.
SEF099P
OK or NG
OK©GO TO 2.
NG©Repair or replace.
2 CHECK HEATED OXYGEN SENSOR 1 (FRONT) CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect heated oxygen sensor 1 (front) harness connector and ECM harness connector.
SEF012XA
3. Check harness continuity between ECM terminal 62 and heated oxygen sensor 1 (front) harness connector terminal 2.
Refer to wiring diagram.
Continuity should exist.
4. Check harness continuity between ECM terminal 62 [or heated oxygen sensor 1 (front) harness connector terminal 2]
and ground.
Continuity should not exist.
5. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 3.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
DTC P0172 FUEL INJECTION SYSTEM FUNCTION (RICH SIDE)QG
Diagnostic Procedure
EC-309

6 CHECK FUNCTION OF INJECTORS
With CONSULT-II
1. Install all parts removed.
2. Start engine.
3. Perform ªPOWER BALANCEº in ªACTIVE TESTº mode with CONSULT-II.
SEF190Y
4. Make sure that each circuit produces a momentary engine speed drop.
Without CONSULT-II
1. Install all parts removed.
2. Start engine.
3. Listen to each injector operating sound.
MEC703B
Clicking noise should be heard.
OK or NG
OK©GO TO 7.
NG©Perform trouble diagnosis for ªINJECTORSº, EC-542.
7 REMOVE INJECTOR
1. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
2. Turn ignition switch ªOFFº.
3. Remove injector assembly. Refer to EC-41.
Keep fuel hose and all injectors connected to injector gallery.
©GO TO 8.
8 CHECK INJECTOR
1. Disconnect all injector harness connectors.
2. Disconnect all ignition coil harness connectors.
3. Prepare pans or saucers under each injectors.
4. Crank engine for about 3 seconds.
Make sure fuel does not drip from injector.
OK or NG
OK (Does not drip)©GO TO 9.
NG (Drips)©Replace the injectors from which fuel is dripping. Always replace O-ring with new one.
DTC P0172 FUEL INJECTION SYSTEM FUNCTION (RICH SIDE)QG
Diagnostic Procedure (Cont'd)
EC-311

SEF463TA
Component DescriptionNJEC0196The fuel tank temperature sensor is used to detect the fuel tem-
perature inside the fuel tank. The sensor modifies a voltage signal
from the ECM. The modified signal returns to the ECM as the fuel
temperature input. The sensor uses a thermistor which is sensitive
to the change in temperature. The electrical resistance of the ther-
mistor decreases as temperature increases.
SEF012P

Fluid temperature
ÉC (ÉF)Voltage*
VResistance
kW
20 (68) 3.5 2.3 - 2.7
50 (122) 2.2 0.79 - 0.90
*: These data are reference values and are measured between ECM terminal 82
(Fuel tank temperature sensor) and ground.
CAUTION:
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.
On Board Diagnosis LogicNJEC0197
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0180
0180+An excessively high or low voltage is sent to ECM.+Harness or connectors
(The sensor circuit is open or shorted.)
+Fuel tank temperature sensor
SEF194Y
DTC Confirmation ProcedureNJEC0198NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 9 seconds
before conducting the next test.
With CONSULT-II
1) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Wait at least 5 seconds.
If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-316.
DTC P0180 FUEL TANK TEMPERATURE SENSOR (WHERE FITTED)QG
Component Description
EC-313

Diagnostic ProcedureNJEC0200
1 CHECK POWER SUPPLY
1. Turn ignition switch ªOFFº.
2. Disconnect fuel level sensor unit harness connector.
JEF135Y
3. Turn ignition switch ªONº.
4. Check voltage between terminal 2 and ground with CONSULT-II or tester.
SEF603Y
OK or NG
OK©GO TO 3.
NG©GO TO 2.
2 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors F111, M73
+Harness connectors M81, B38
+Harness for open or short between ECM and fuel level sensor unit
©Repair harness or connector.
3 CHECK GROUND CIRCUIT
1. Turn ignition switch ªOFFº.
2. Check harness continuity between fuel level sensor unit harness connector terminal 1 and body ground.
Refer to wiring diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 5.
NG (Sedan)©Repair open circuit or short to ground or short to power in harness or connectors.
NG (Hatchback)©GO TO 4.
DTC P0180 FUEL TANK TEMPERATURE SENSOR (WHERE FITTED)QG
Diagnostic Procedure
EC-316