
h)Fuel pressure
i)Engine compression
j)EGR valve operation
k)Throttle valve
l)EVAP system
+On models equipped with air conditioner, checks should
be carried out while the air conditioner is ªOFFº.
+When checking idle speed on models equipped with A/T,
ignition timing and mixture ratio, checks should be carried
out while shift lever is in ªPº or ªNº position.
+When measuring ªCOº percentage, insert probe more
than 40 cm (15.7 in) into tail pipe.
+Turn off headlamps, heater blower, rear window defogger.
+On vehicles equipped with daytime light systems, set
lighting switch to the 1st position to light only small
lamps.
+Keep front wheels pointed straight ahead.
+If engine stops immediately after starting or idle condition
is unstable, perform the following to initialize IACV-AAC
valve:
a)Stop engine and wait 9 seconds.
b)Turn ignition ªONº and wait 1 second.
c)Turn ignition ªOFFº and wait 9 seconds.
+Make sure the cooling fan has stopped.
BASIC SERVICE PROCEDUREQG
Preparation (Cont'd)
EC-43

21 CHECK HEATED OXYGEN SENSOR 1 (FRONT) SIGNAL
With CONSULT-II
1. Stop engine.
2. Replace heated oxygen sensor 1 (front).
3. Start engine and warm it up to normal operating temperature.
4. Run engine at approx. 2,000 rpm for approx. 2 minutes under no-load.
5. See ªHO2S1 MNTR (B1)º in ªDATA MONITORº mode.
6. Running engine at 2,000 rpm under no-load (engine is warmed up to normal operating temperature.), check that the
monitor fluctuates between ªLEANº and ªRICHº more than 5 times during 10 seconds.
1 time: RICH®LEAN®RICH
2 times: RICH®LEAN®RICH®LEAN®RICH
Without CONSULT-II
1. Stop engine.
2. Replace heated oxygen sensor 1 (front).
3. Start engine and warm it up to normal operating temperature.
4. Run engine at approx. 2,000 rpm for approx. 2 minutes under no-load.
5. Set voltmeter probe between ECM terminal 62 and ground.
6. Make sure that the voltage fluctuates between 0 to 0.3V and 0.6 to 1.0V more than 5 times during 10 seconds at 2,000
rpm.
1 time: 0 - 0.3V®0.6 - 1.0V®0 - 0.3V
2 times: 0 - 0.3V®0.6 - 1.0V®0 - 0.3V®0.6 - 1.0V®0 - 0.3V
OK or NG
OK©INSPECTION END
NG©GO TO 22.
22 DETECT MALFUNCTIONING PART
Check the following.
1. Check fuel pressure regulator. Refer to EC-39.
2. Check mass air flow sensor and its circuit. Refer to EC-152.
3. Check injector and its circuit. Refer to EC-446.
Clean or replace if necessary.
4. Check engine coolant temperature sensor and its circuit. Refer to EC-163.
5. Check ECM function by substituting another known-good ECM.
(ECM may be the cause of a problem, but this is rarely the case.)
©GO TO 3.
23 CHECK HEATED OXYGEN SENSOR 1 (FRONT) HARNESS
1. Turn off engine and disconnect battery ground cable.
2. Disconnect ECM harness connector.
3. Disconnect heated oxygen sensor 1 (front) harness connector.
4. Check harness continuity between ECM terminal 62 and heated oxygen sensor 1 (front) harness connector terminal 1.
Refer to Wiring Diagram, EC-176.
Continuity should exist.
OK or NG
OK©GO TO 25.
NG©GO TO 24.
24 REPAIR OR REPLACE
Repair or replace harness between ECM and heated oxygen sensor 1 (front).
©GO TO 3.
BASIC SERVICE PROCEDUREQG
Inspection Procedure (Cont'd)
EC-51

27 CHECK HEATED OXYGEN SENSOR 1 (FRONT) SIGNAL
With CONSULT-II
1. Stop engine.
2. Replace heated oxygen sensor 1 (front).
3. Start engine and warm it up to normal operating temperature.
4. Run engine at approx. 2,000 rpm for approx. 2 minutes under no-load.
5. See ªHO2S1 MNTR (B1)º in ªDATA MONITORº mode.
6. Maintaining engine at 2,000 rpm under no-load (engine is warmed up to normal operating temperature.), check that the
monitor fluctuates between ªLEANº and ªRICHº more than 5 times during 10 seconds.
1 time: RICH®LEAN®RICH
2 times: RICH®LEAN®RICH®LEAN®RICH
Without CONSULT-II
1. Stop engine.
2. Replace heated oxygen sensor 1 (front).
3. Start engine and warm it up to normal operating temperature.
4. Run engine at approx. 2,000 rpm for approx. 2 minutes under no-load.
5. Set voltmeter probe between ECM terminal 62 and ground.
6. Make sure that voltage fluctuates between 0 - 0.3V and 0.6 - 1.0V more than 5 times during 10 seconds at 2,000 rpm.
1 time: 0 - 0.3V®0.6 - 1.0V®0 - 0.3V
2 times: 0 - 0.3V®0.6 - 1.0V®0 - 0.3V®0.6 - 1.0V®0 - 0.3V
OK or NG
OK©GO TO 3.
NG©GO TO 28.
28 DETECT MALFUNCTIONING PART
Check the following.
+Connect heated oxygen sensor 1 (front) harness connectors to heated oxygen sensors 1 (front).
+Check fuel pressure regulator. Refer to EC-39.
+Check mass air flow sensor and its circuit. Refer to EC-152.
+Check injector and its circuit. Refer to EC-446.
Clean or replace if necessary.
+Check engine coolant temperature sensor and its circuit. Refer to EC-163.
+Check ECM function by substituting another known-good ECM.
(ECM may be the cause of a problem, but this is rarely the case.)
©GO TO 3.
BASIC SERVICE PROCEDUREQG
Inspection Procedure (Cont'd)
EC-54

5) System readiness test (SRT) codes
6) Test values
7) Distance traveled while MI is activated.
8) Others
WORK SUPPORT MODENJEC0034S04
WORK ITEM CONDITION USAGE
TP SW/TP SEN IDLE POSI ADJ+FOLLOW THE BASIC INSPECTION INSTRUCTION IN
THE SERVICE MANUAL.When adjusting the idle throttle
position
FUEL PRESSURE RELEASE+FUEL PUMP WILL STOP BY TOUCHING ªSTARTº
DURING IDLING.
CRANK A FEW TIMES AFTER ENGINE STALLS.When releasing fuel pressure
from fuel line
IDLE AIR VOL LEARN+THE IDLE AIR VOLUME THAT KEEPS THE ENGINE
WITHIN THE SPECIFIED RANGE IS MEMORIZED IN
ECM.When learning the idle air volume
SELF-LEARNING CONT+THE COEFFICIENT OF SELF-LEARNING CONTROL
MIXTURE RATIO RETURNS TO THE ORIGINAL
COEFFICIENT.When clear the coefficient of self-
learnign control value
TARGET IDLE RPM ADJ*+IDLE CONDITION When setting target idle speed
TARGET IGNITION TIMING ADJ*+IDLE CONDITION When adjusting target ignition tim-
ing
After adjustment, confirm target
ignition timing with a timing light.
+If once the ªTARGET IDLE
RPM ADJº has been done, the
Idle Air Volume Learning proce-
dure will not be completed.
*: This function is not necessary in the usual service procedure.
SELF DIAGNOSTIC MODENJEC0034S05DTC and 1st Trip DTCNJEC0034S0501Regarding items of ªDTC and 1st trip DTCº, refer to
ªTROUBLE DIAGNOSIS Ð INDEXº, EC-10.
Freeze Frame Data and 1st Trip Freeze Frame DataNJEC0034S0502
Freeze frame data
item*Description
DIAG TROUBLE
CODE
[PXXXX]+Engine Control component part/control system has a trouble code, it is displayed as ªPXXXXº. (Refer to
ªAlphabetical & P No. Index for DTCº, EC-10.)
FUEL SYS-B1+ªFuel injection system statusº at the moment a malfunction is detected is displayed.
+One mode in the following is displayed.
ªMODE 2º: Open loop due to detected system malfunction
ªMODE 3º: Open loop due to driving conditions (power enrichment, deceleration enrichment)
ªMODE 4º: Closed loop - using oxygen sensor(s) as feedback for fuel control
ªMODE 5º: Open loop - has not yet satisfied condition to go to closed loop
CAL/LD VALUE [%]+The calculated load value at the moment a malfunction is detected is displayed.
COOLANT TEMP [ÉC]
or [ÉF]+The engine coolant temperature at the moment a malfunction is detected is displayed.
L-FUEL TRIM-B1 [%]+ªLong-term fuel trimº at the moment a malfunction is detected is displayed.
+The long-term fuel trim indicates much more gradual feedback compensation to the base fuel schedule
than short-term fuel trim.
S-FUEL TRIM-B1 [%]+ªShort-term fuel trimº at the moment a malfunction is detected is displayed.
+The short-term fuel trim indicates dynamic or instantaneous feedback compensation to the base fuel
schedule.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG
CONSULT-II (Cont'd)
EC-84
![NISSAN ALMERA N16 2001 Electronic Repair Manual Monitored item [Unit]ECM
input
signalsMain
signalsDescription Remarks
HO2S2 MNTR (B1)
[RICH/LEAN]j+Display of heated oxygen sensor 2 (rear)
signal:
RICH ... means the amount of oxygen after
three way NISSAN ALMERA N16 2001 Electronic Repair Manual Monitored item [Unit]ECM
input
signalsMain
signalsDescription Remarks
HO2S2 MNTR (B1)
[RICH/LEAN]j+Display of heated oxygen sensor 2 (rear)
signal:
RICH ... means the amount of oxygen after
three way](/manual-img/5/57351/w960_57351-381.png)
Monitored item [Unit]ECM
input
signalsMain
signalsDescription Remarks
HO2S2 MNTR (B1)
[RICH/LEAN]j+Display of heated oxygen sensor 2 (rear)
signal:
RICH ... means the amount of oxygen after
three way catalyst is relatively small.
LEAN ... means the amount of oxygen after
three way catalyst is relatively large.+When the engine is stopped, a cer-
tain value is indicated.
VHCL SPEED SE
[km/h] or [mph]jj+The vehicle speed computed from the
vehicle speed sensor signal is displayed.
BATTERY VOLT [V]j+The power supply voltage of ECM is dis-
played.
THRTL POS SEN [V]jj+The throttle position sensor signal voltage is
displayed.
FUEL T/TMP SE
[ÉC] or [ÉF]*+The fuel temperature judged from the fuel
tank temperature sensor signal voltage is
displayed.
INT/A TEMP SE
[ÉC] or [ÉF]j+The intake air temperature determined by
the signal voltage of the intake air tempera-
ture sensor is indicated.
EGR TEMP SEN [V]*jj+The signal voltage of the EGR temperature
sensor is displayed.
START SIGNAL
[ON/OFF]jj+Indicates [ON/OFF] condition from the
starter signal.+After starting the engine, [OFF] is
displayed regardless of the starter
signal.
CLSD THL POS
[ON/OFF]jj+Indicates idle position [ON/OFF] computed
by ECM according to the throttle position
sensor signal.
CLSD THL/P SW
[ON/OFF]*j+Indicates mechanical contact [ON/OFF]
condition of the closed throttle position
switch.
AIR COND SIG
[ON/OFF]jj+Indicates [ON/OFF] condition of the air con-
ditioner switch as determined by the air
conditioning signal.
P/N POSI SW
[ON/OFF]jj+Indicates [ON/OFF] condition from the PNP
switch signal.
PW/ST SIGNAL
[ON/OFF]jj+Indicates [ON/OFF] condition of the power
steering oil pressure switch determined by
the power steering oil pressure switch sig-
nal.
LOAD SIGNAL
[ON/OFF]jj+Indicates [ON/OFF] condition from the elec-
trical load signal and/or lighting switch.
ON ... rear defogger is operating and/or
lighting switch is on.
OFF ... rear defogger is not operating and
lighting switch is not on.
IGNITION SW
[ON/OFF]j+Indicates [ON/OFF] condition from ignition
switch.
HEATER FAN SW
[ON/OFF]j+Indicates [ON/OFF] condition from the
heater fan switch.
INJ PULSE-B1
[msec]j+Indicates the actual fuel injection pulse
width compensated by ECM according to
the input signals.+When the engine is stopped, a cer-
tain computed value is indicated.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG
CONSULT-II (Cont'd)
EC-86

Symptom Matrix ChartNJEC0041SYSTEM Ð ENGINE CONTROL SYSTEMNJEC0041S01
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Fuel Fuel pump circuit11232 22 3 2EC-464
Fuel pressure regulator sys-
tem334444444 4EC-39
Injector circuit11232 22 2EC-447
Evaporative emission sys-
tem334444444 4EC-33
Air Positive crankcase ventila-
tion system334444444 41EC-37
Incorrect idle speed adjust-
ment3 3 1 1 1 1 1 EC-41
IACV-AAC valve circuit112332222 2 2EC-313
Ignition Incorrect ignition timing
adjustment33111 11 1EC-41
Ignition circuit11222 22 2EC-451
EGR EGR volume control valve
circuit2233 3EC-293
EGR system212333223 3EC-285,
293, 353
Main power supply and ground circuit22333 33 23 2EC-145
Air conditioner circuit223333333 3 2HAsection
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONQG
Symptom Matrix Chart
EC-124

SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Crankshaft position sensor (POS)
circuit22EC-272
Camshaft position sensor
(PHASE) circuit3 2 3 EC-278
Mass air flow sensor circuit11222 22 2EC-152
Heated oxygen sensor 1 (front)
circuit1232 22 2EC-176,
183
Engine coolant temperature sen-
sor circuit112323223 2EC-163,
165
Throttle position sensor circuit 1 222222 2EC-168
Incorrect throttle position sensor
adjustment31 11111 1EC-98
Vehicle speed sensor circuit 2 3 3 3 EC-309
Knock sensor circuit 2 3 EC-268
ECM 22333333333EC-327,
123
Start signal circuit 2EC-461
PNP switch circuit 3 3 3 3 3 EC-364
Power steering oil pressure switch
circuit2 3 3 EC-471
Electrical load signal circuit 3 3 EC-480
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONQG
Symptom Matrix Chart (Cont'd)
EC-125

DescriptionNJEC1265The specification (SP) value indicates the tolerance of the value that is displayed in ªDATA MONITOR (SPEC)º
mode of CONSULT-II during normal operation of the Engine Control System. When the value in ªDATA MONI-
TOR (SPEC)º mode is within the SP value, the Engine Control System is confirmed OK. When the value in
ªDATA MONITOR (SPEC)º mode is NOT within the SP value, the Engine Control System may have one or
more malfunctions.
The SP value is used to detect malfunctions that may affect the Engine Control System, but will not light the
MIL.
The SP value will be displayed for the following three items:
+B/FUEL SCHDL (The fuel injection pulse width programmed into ECM prior to any learned on board cor-
rection)
+A/F ALPHA-B1 (The mean value of air-fuel ratio feedback correction factor per cycle)
+MAS A/F SE-B1 (The signal voltage of the mass air flow sensor)
Testing ConditionNJEC1266+Vehicle driven distance: More than 5,000 km (3,017 miles)
+Barometric pressure: 98.3 - 104.3 kPa (0.983 - 1.043 bar, 1.003 - 1.064 kg/cm2, 14.25 - 15.12 psi)
+Atmospheric temperature: 20 - 30ÉC (68 - 86ÉF)
+Engine coolant temperature: 75 - 95ÉC (167 - 203ÉF)
+Transmission: Warmed-up*1
+Electrical load: Not applied*2
+Engine speed: Idle
*1: For A/T or CVT models, after the engine is warmed up to normal operating temperature, drive vehicle until
ªFLUID TEMP SEº (A/T or CVT fluid temperature sensor signal) indicates less than 0.9V. For M/T models, drive
vehicle for 5 minutes after the engine is warmed up to normal operating temperature.
*2: Rear window defogger switch, air conditioner switch, lighting switch are ªOFFº. Cooling fans are not oper-
ating. Steering wheel is straight ahead.
SEF601Z
Inspection ProcedureNJEC1267NOTE:
Perform ªDATA MONITOR (SPEC)º mode in maximum scale dis-
play.
1. Perform ªBasic Inspectionº, EC-98.
2. Confirm that the testing conditions indicated above are met.
3. Select ªB/FUEL SCHDLº, ªA/F ALPHA-B1º and ªMAS A/F
SE-B1º in ªDATA MONITOR (SPEC)º mode with CONSULT-II.
4. Make sure that monitor items are within the SP value.
5. If NG, go to ªDiagnostic Procedureº, EC-141.
TROUBLE DIAGNOSIS Ð SPECIFICATION VALUEQG
Description
EC-140