2001 NISSAN ALMERA N16 Mass air flow sensor

Monitored item
[Unit]ECM
input
signalsMain
signalsDescription Remarks
SPILL/V [ÉCA]
j+The control position of spill valve (sent
from electronic control fuel injection
pump) is displayed.
BATTERY VOLT [V]
jj+The power supply voltage of ECM is
displayed.
P/N POSI SW*1
[ON/OFF] (where
fitted)jj+Indicates [ON/OFF] condition from the
park/neutral position switch signal.
START SIGNAL
[ON/OFF]jj+Indicates [ON/OFF] condition from the
starter signal.+After starting the engine, [OFF] is dis-
played regardless of the starter signal.
BRAKE SW
[ON/OFF]jj+Indicates [ON/OFF] condition from the
stop lamp switch signal.
BRAKE SW2
[ON/OFF]jj+Indicates [ON/OFF] condition from the
brake pedal position switch signal.
IGN SW
[ON/OFF]jj+Indicates [ON/OFF] condition from igni-
tion switch signal.
MAS AIR/FL SE [V]
jj+The signal voltage of the mass air flow
sensor is displayed.+When the engine is stopped, a certain
value is indicated.
INT/A VOLUME [mg/]+The intake air volume computed from
the mass air flow sensor signal is dis-
played.
F/CUT SIGNAL
[ON/OFF]
j+The [ON/OFF] condition from decelera-
tion fuel cut signal (sent from electronic
control fuel injection pump) is displayed.
OFF´´´Fuel is cut off.
ON´´´Fuel is not cut off.
GLOW RLY
[ON/OFF]j+The glow relay control condition (deter-
mined by ECM according to the input
signal) is displayed.
COOLING FAN
[LOW/HI/OFF]
j+Indicates the control condition of the
cooling fans (determined by ECM
according to the input signal).
+LOW ... Operates at low speed.
HI ... Operates at high speed.
OFF ... Stopped.
BARO SEN [kPa]
jj+The barometric pressure (determined
by the signal voltage from the baromet-
ric pressure sensor built into the ECM)
is displayed.
EGR VOL CON/V
[step]
j+Indicates the EGR volume control value
computed by the ECM according to the
input signals.
+The opening becomes larger as the
value increases.
*1: On models not equipped with park/neutral position (PNP) switch, ªOFFº is always displayed regardless of gear shift position.
NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONYD
CONSULT-II (Cont'd)
EC-529

3 CHECK IDLE SPEED
With CONSULT-II
1. Select ªCKPS´RPM (TDC)º in ªDATA MONITORº mode with CONSULT-II.
2. Read idle speed.
SEF817Y
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-520.
©GO TO 6.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONYD
Basic Inspection (Cont'd)
EC-537

SYSTEM Ð ENGINE CONTROL system
Malfunction
SYMPTOM
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
ENGINE CONTROL
Electronic control fuel injection
pump circuit*a, *b 1 1
111111111
Ð
*c, *d
Mass air flow sensor circuit*a, *c
111
EC-566
*b
Engine coolant temperature sensor
circuit*a, *b 1 1 1 1 EC-572 *1
Vehicle speed sensor circuit *a, *b 1 EC-593
1 - 5: The numbers refer to the order of inspection.
(continued on next page)
*a: Open
*b: Short
*c: Ground short
*d: Noise
*1: Compensation according to engine coolant temperature does not function.
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONYD
Symptom Matrix Chart (Cont'd)
EC-543

SYSTEM Ð ENGINE CONTROL system
Malfunction
SYMPTOM
Reference page
Feature of symptom, Check pointROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEAT/HIGH ENGINE COOLANT TEMPERATURE
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
ABNORMAL SMOKE COLOR
DEAD BATTERY (UNDER CHARGE)
Malfunction indicator illuminates.
Can be detected by CONSULT-II?BLACK SMOKE
WHITE SMOKEWarranty symptom code AG AH AJ AK AL AM AP HA
ENGINE CONTROL
Electronic control fuel injection pump
circuit*a, *b 1 1 1
11 Ð
*c, *d 1
Mass air flow sensor circuit*a, *c
1 EC-566
*b 1
Engine coolant temperature sensor cir-
cuit*a, *b 1 1 1 1 1 EC-572 *1
Vehicle speed sensor circuit *a, *b 1 EC-593
1 - 5: The numbers refer to the order of inspection.
(continued on next page)
*a: Open
*b: Short
*c: Ground short
*d: Noise
*1: Compensation according to engine coolant temperature does not function.
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONYD
Symptom Matrix Chart (Cont'd)
EC-544

TERMI-
NAL
NO.WIRE
COLORITEM CONDITIONDATA (DC Voltage and Pulse
Signal)
204 L Air conditioner relay[Engine is running]
+Air conditioner switch is ªOFFºBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
+Both air conditioner switch and blower fan
switch are ªONº
(Compressor is operating)Approximately 0.1V
214 W/B Glow relay Refer to ªGlow Control Systemº, EC-677.
218 B Sensors' ground[Engine is running]
+Warm-up condition
+Idle speedApproximately 0V
219 LG/R Cooling fan relay (Low)[Engine is running]
+Cooling fan is not operatingBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
+Cooling fan is operatingApproximately 0.1V
221 LG/B Cooling fan relay (High)[Engine is running]
+Cooling fan is not operating
+Cooling fan is operating at low speedBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
+Cooling fan is operating at high speedApproximately 0.1V
223 WMass air flow sensor
power supply[Ignition switch ªONº]Approximately 5V
224 R Mass air flow sensor[Engine is running]
+Warm-up condition
+Idle speed1.5 - 2.0V
313 L/WElectronic control fuel
injection pump[Engine is running]
+Warm-up condition
+Idle speedApproximately 0.1V
314 L/RElectronic control fuel
injection pump[Engine is running]
+Warm-up condition
+Idle speedApproximately 0.4V
316 PUElectronic control fuel
injection pump[Engine is running]
+Warm-up condition
+Idle speedApproximately 2.5V
317 PElectronic control fuel
injection pump[Engine is running]
+Warm-up condition
+Idle speedApproximately 2.5V
325 G ECM relay (Self-shutoff)[Ignition switch ªONº]
[Ignition switch ªOFFº]
+For a few seconds after turning ignition switch
ªOFFºApproximately 0.25V
[Ignition switch ªOFFº]
+A few seconds passed after turning ignition
switch ªOFFºBATTERY VOLTAGE
(11 - 14V)
331 ORCrankshaft position sen-
sor (TDC) ground[Engine is running]
+Warm-up condition
+Idle speedApproximately 0V
334 B/REngine coolant tempera-
ture sensor ground[Ignition switch ªONº]Approximately 0V
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONYD
ECM Terminals and Reference Value (Cont'd)
EC-555

SEF987W
Component DescriptionNJEC0642The mass air flow sensor (MAFS) is placed in the stream of intake
air. It measures the intake air flow rate by measuring a part of the
entire intake air flow. It consists of a hot film that is supplied with
electric current from the ECM. The temperature of the hot film is
controlled by the ECM a certain amount. The heat generated by the
hot film is reduced as the intake air flows around it. The more air,
the greater the heat loss.
Therefore, the ECM must supply more electric current to maintain
the temperature of the hot film as air flow increases. The ECM
detects the air flow by means of this current change.
CONSULT-II Reference Value in Data Monitor
Mode
NJEC0643Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
MAS AIR/FL SE+Engine: After warming up
+Air conditioner switch: ªOFFº
+Shift lever: Neutral position
+No-loadIdle 1.5 - 2.0V
ECM Terminals and Reference ValueNJEC0644Specification data are reference values, and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
218 B Sensor's ground[Engine is running]
+Warm-up condition
+Idle speedApproximately 0V
223 WMass air flow sensor
power supply[Ignition switch ªONº]Approximately 5V
224 R Mass air flow sensor[Engine is running]
+Warm-up condition
+Idle speed1.5 - 2.0V
On Board Diagnosis LogicNJEC0645
DTC Malfunction is detected when ... Check Items (Possible Cause)
P0100
0102+An excessively high or low voltage from the sen-
sor is sent to ECM.+Harness or connectors
(The sensor circuit is open or shorted.)
+Mass air flow sensor
SEF817Y
DTC Confirmation ProcedureNJEC0646WITH CONSULT-IINJEC0646S011) Turn ignition switch ªONº, and wait at least 6 seconds.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Start engine and wait at least 3 seconds.
4) If DTC is detected, go to ªDiagnostic Procedureº, EC-569.
WITHOUT CONSULT-IINJEC0646S021) Turn ignition switch ªONº, and wait at least 6 seconds.
2) Start engine and wait at least 3 seconds.
DTC P0100 MASS AIR FLOW SENYD
Component Description
EC-566

Diagnostic ProcedureNJEC0648
1 CHECK MAFS POWER SUPPLY CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect mass air flow sensor harness connector.
SEF884Y
3. Turn ignition switch ªONº.
4. Check voltage between mass air flow sensor terminals 2, 4 and ground with CONSULT-II or tester.
SEF297X
OK or NG
OK©GO TO 3.
NG©GO TO 2.
2 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors E75, F36
+Harness for open or short between mass air flow sensor and ECM
+Harness for open or short between mass air flow sensor and ECM relay
©Repair open circuit or short to ground or short to power in harness or connector.
DTC P0100 MASS AIR FLOW SENYD
Diagnostic Procedure
EC-569

3 CHECK MAFS GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screws.
SEF380Y
3. Check harness continuity between mass air flow sensor terminal 3 and engine ground. Refer to Wiring Diagram.
Continuity should exist.
4. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 5.
NG©GO TO 4.
4 DETECT MALFUNCTIONING PART
Check harness for open or short between mass air flow sensor and ECM.
©Repair open circuit or short to ground or short to power in harness or connectors.
5 CHECK MAFS INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between mass air flow sensor terminal 1 and ECM terminal 224. 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 6.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
DTC P0100 MASS AIR FLOW SENYD
Diagnostic Procedure (Cont'd)
EC-570