NISSAN ALMERA 2001 Service Manual
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IntroductionNJEC0630The engine has an ECM to control major systems such as fuel
injection control, fuel injection timing control, glow control system,
etc. The ECM accepts input signals from sensors and instantly
drives electronic control fuel injection pump. It is essential that both
input and output signals are proper and stable. At the same time,
it is important that there are no problems such as vacuum leaks,
or other problems with the engine.
It is much more difficult to diagnose a problem that occurs intermit-
tently rather than continuously. Most intermittent problems are
caused by poor electric connections or improper wiring. In this
case, careful checking of suspected circuits may help prevent the
replacement of good parts.
A visual check only may not find the cause of the problems. A road
test with CONSULT-II or a circuit tester connected should be per-
formed. Follow the ªWork Flowº, EC-639.
Before undertaking actual checks, take a few minutes to talk with
a customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such problems, espe-
cially intermittent ones. Find out what symptoms are present and
under what conditions they occur. A ªDiagnostic Worksheetº like the
example on next page should be used.
Start your diagnosis by looking for ªconventionalº problems first.
This will help troubleshoot driveability problems on an electronically
controlled engine vehicle.
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DIAGNOSTIC WORKSHEETNJEC0630S01There are many operating conditions that lead to the malfunction
of engine components. A good grasp of such conditions can make
troubleshooting faster and more accurate.
In general, each customer feels differently about a problem. It is
important to fully understand the symptoms or conditions for a
customer complaint.
Utilize a diagnostic worksheet like the one shown below in order to
organize all the information for troubleshooting.
TROUBLE DIAGNOSIS Ð INTRODUCTIONYD
EC-637
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Worksheet SampleNJEC0630S0101
MTBL0533
TROUBLE DIAGNOSIS Ð INTRODUCTIONYD
Introduction (Cont'd)
EC-638
Page 1363 of 2898
Work FlowNJEC0631
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*1 EC-625
*2 If time data of ªSELF-DIAG
RESULTSº is other than ª0º, per-
form ªTROUBLE DIAGNOSIS
FOR INTERMITTENT INCIDENTº,
EC-665.*3 If the incident cannot be verified,
perform ªTROUBLE DIAGNOSIS
FOR INTERMITTENT INCIDENTº,
EC-665.
*4 If the on board diagnostic system
cannot be performed, check main
power supply and ground circuit.Refer to ªTROUBLE DIAGNOSIS
FOR POWER SUPPLYº, EC-666.
*5 If malfunctioning part cannot be
detected, perform ªTROUBLE
DIAGNOSIS FOR INTERMIT-
TENT INCIDENTº, EC-665.
TROUBLE DIAGNOSIS Ð INTRODUCTIONYD
Work Flow
EC-639
Page 1364 of 2898
DESCRIPTION FOR WORK FLOWNJEC0631S01
STEP DESCRIPTION
STEP IGet detailed information about the conditions and the environment when the incident/symptom occurred using
the ªDIAGNOSTIC WORKSHEETº, EC-637.
STEP IIBefore confirming the concern, check and write down (print out using CONSULT-II) the DTC, then erase the
DTC. Refer to EC-627.
If the incident cannot be verified, perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-665.
Study the relationship between the cause, specified by DTC, and the symptom described by the customer. (The
ªSymptom Matrix Chartº will be useful. Refer to EC-646.) Also check related service bulletins for information.
STEP IIITry to confirm the symptom and under what conditions the incident occurs.
The ªDIAGNOSTIC WORK SHEETº is useful to verify the incident. Connect CONSULT-II to the vehicle in DATA
MONITOR (AUTO TRIG) mode and check real time diagnosis results.
If the incident cannot be verified, perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-665.
If the malfunction code is detected, skip STEP IV and perform STEP V.
STEP IVTry to detect the DTC by driving in (or performing) the ªDTC Confirmation Procedureº. Check and read the DTC
by using CONSULT-II.
During the DTC verification, be sure to connect CONSULT-II to the vehicle in DATA MONITOR (AUTO TRIG)
mode and check real time diagnosis results.
If the incident cannot be verified, perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-665.
In case the ªDTC Confirmation Procedureº is not available, perform the ªOverall Function Checkº instead. The
DTC cannot be displayed by this check, however, this simplified ªcheckº is an effective alternative.
The ªNGº result of the ªOverall Function Checkº is the same as the DTC detection.
STEP VTake the appropriate action based on the results of STEP I through IV.
If the malfunction code is indicated, proceed to TROUBLE DIAGNOSIS FOR DTC PXXXX.
If the normal code is indicated, proceed to the Basic Inspection, EC-641. Then perform inspections according to
the Symptom Matrix Chart. Refer to EC-646.
STEP VIIdentify where to begin diagnosis based on the relationship study between symptom and possible causes.
Inspect the system for mechanical binding, loose connectors or wiring damage using (tracing) ªHarness Layoutsº.
Gently shake the related connectors, components or wiring harness with CONSULT-II set in ªDATA MONITOR
(AUTO TRIG)º mode.
Check the voltage of the related ECM terminals or monitor the output data from the related sensors with CON-
SULT-II. Refer to EC-659 or EC-656.
The ªDiagnostic Procedureº in EC section contains a description based on open circuit inspection. A short circuit
inspection is also required for the circuit check in the Diagnostic Procedure. For details, refer to GI-24, ªCircuit
Inspectionº.
Repair or replace the malfunction parts.
If the malfunctioning part cannot be detected, perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT
INCIDENTº, EC-665.
STEP VIIOnce you have repaired the circuit or replaced a component, you need to run the engine in the same conditions
and circumstances which resulted in the customer's initial complaint.
Perform the ªDTC Confirmation Procedureº and confirm the normal code (DTC P0000 or 0505) is detected. If the
incident is still detected in the final check, perform STEP VI by using a different method from the previous one.
Before returning the vehicle to the customer, be sure to erase the unnecessary (already fixed) DTC in ECM.
(Refer to EC-627.)
TROUBLE DIAGNOSIS Ð INTRODUCTIONYD
Work Flow (Cont'd)
EC-640
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Basic InspectionNJEC0632Precaution:
Perform Basic Inspection without electrical or mechanical
loads applied;
+Headlamp switch is OFF,
+On vehicles equipped with daytime light systems, set
lighting switch to the 1st position to light only small
lamps.
+Air conditioner switch is OFF,
+Rear defogger switch is OFF,
+Steering wheel is in the straight-ahead position, etc.
1 INSPECTION START
1. Check service records for any recent repairs that may indicate a related problem.
2. Check the current need for scheduled maintenance, especially for fuel filter and air cleaner filter. Refer to MA-6, ªPeri-
odic Maintenanceº.
3. Open engine hood and check the following:
+Harness connectors for improper connections
+Vacuum hoses for splits, kinks, or improper connections
+Wiring for improper connections, pinches, or cuts
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4. Start engine and warm it up to the normal operating temperature.
©GO TO 2.
2 PREPARATION FOR CHECKING IDLE SPEED
With CONSULT-II
Connect CONSULT-II to the data link connector.
Without CONSULT-II
Install diesel tacho tester to the vehicle.
©GO TO 3.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONYD
Basic Inspection
EC-641
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3 CHECK IDLE SPEED
With CONSULT-II
1. Select ªCKPS´RPM (TDC)º in ªDATA MONITORº mode with CONSULT-II.
2. Read idle speed.
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Without CONSULT-II
Check idle speed.
725±25 rpm
OK or NG
OK©INSPECTION END
NG©GO TO 4.
4 CHECK FOR INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK©GO TO 5.
NG©Repair or replace.
5 BLEED AIR FROM FUEL SYSTEM
1. Stop engine.
2. Use priming pump to bleed air from fuel system. Refer to ªAIR BLEEDINGº, EC-625.
©GO TO 6.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONYD
Basic Inspection (Cont'd)
EC-642
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6 CHECK IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and let it idle.
2. Select ªCKPS´RPM (TDC)º in ªDATA MONITORº mode with CONSULT-II.
3. Read idle speed.
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Without CONSULT-II
1. Start engine and let it idle.
2. Check idle speed.
725±25 rpm
OK or NG
OK©INSPECTION END
NG©GO TO 7.
7 DRIN WATER FROM FUEL FILTER
Drain water from fuel filter. Refer to ªWATER DRAININGº, EC-625.
©GO TO 8.
8 CHECK IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and let it idle.
2. Select ªCKPS´RPM (TDC)º in ªDATA MONITORº mode with CONSULT-II.
3. Read idle speed.
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Without CONSULT-II
1. Start engine and let it idle.
2. Check idle speed.
725±25 rpm
OK or NG
OK©INSPECTION END
NG©GO TO 9.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONYD
Basic Inspection (Cont'd)
EC-643
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9 CHECK AIR CLEANER FILTER
Check air cleaner filter for clogging or braks.
OK or NG
OK©GO TO 10.
NG©Replace air cleaner filter.
10 CHECK FUEL INJECTION NOZZLE
Check fuel injection nozzle opening pressure. Refer to ªInjection Pressure Testº, EC-617.
OK or NG
OK©GO TO 11.
NG©Replace fuel injection nozzle assembly.
11 CHECK IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and let it idle.
2. Select ªCKPS´RPM (TDC)º in ªDATA MONITORº mode with CONSULT-II.
3. Read idle speed.
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Without CONSULT-II
1. Start engine and let it idle.
2. Check idle speed.
725±25 rpm
OK or NG
OK©INSPECTION END
NG©GO TO 12.
12 CHECK COMPRESSION PRESSURE
Check compression pressure. Refer to EM-83, ªMEASUREMENT OF COMPRESSION PRESSUREº.
OK or NG
OK©GO TO 13.
NG©Follow the instruction of ªMEASUREMENT OF COMPRESSION PRESSUREº.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONYD
Basic Inspection (Cont'd)
EC-644
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13 CHECK IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and let it idle.
2. Select ªCKPS´RPM (TDC)º in ªDATA MONITORº mode with CONSULT-II.
3. Read idle speed.
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Without CONSULT-II
1. Start engine and let it idle.
2. Check idle speed.
725±25 rpm
OK or NG
OK©INSPECTION END
NG©Replace electronic control fuel injection pump.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONYD
Basic Inspection (Cont'd)
EC-645
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Symptom Matrix ChartNJEC1257
SYSTEM Ð Basic engine
control systemSYMPTOM
Reference page
Feature of symptom, Check pointHARD/NO START/RESTART
(EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
KNOCK/DETONATION
LACK OF POWER
POOR ACCELERATION
HI IDLE
LOW IDLE NO START (with first firing)
NO START (without first firing)
HARD TO START WHEN ENGINE IS COLD
HARD TO START WHEN ENGINE IS HOT
AT IDLE
DURING DRIVING
WHEN DECELERATINGWarranty symptom code AA AB AC AD AE AF
Electronic control fuel injec-
tion pump mainframe4444444445544 Ð *1
Injection nozzle3333333334433EC-614 *2
Glow system1111 1EC-806
Engine body3333333 344 3EMsection *3
EGR system3 3 EC-815
Air cleaner and ducts 3 3 MA section *4
1 - 5: The numbers refer to the order of inspection.
(continued on next page)
*1: Fuel injection system malfunction or fuel injection timing control system malfunction may be the cause.
*2: Depends on open-valve pressure and spray pattern.
*3: Caused mainly by insufficient compression pressure.
*4: Symptom varies depending on off-position of air duct, etc.
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONYD
Symptom Matrix Chart
EC-646