2001 NISSAN ALMERA N16 electrical

DescriptionNJEC1746SYSTEM DESCRIPTIONNJEC1746S01
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS) Engine speed
EGR vol-
ume controlEGR volume control valve Camshaft position sensor (PHASE) Engine speed and cylinder number
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Throttle position sensor Throttle position
Vehicle speed sensor Vehicle speed
Battery Battery voltage
Air conditioner switch Air conditioner operation
Power steering oil pressure switch Power steering load signal
Electrical load Electrical load signal
PNP switch Park/Neutral position signal
This system controls flow rate of EGR led from exhaust manifold
to intake manifold. The opening of the EGR by-pass passage in the
EGR volume control valve changes to control the flow rate. A
built-in step motor moves the valve in steps corresponding to the
ECM output pulses. The opening of the valve varies for optimum
engine control. The optimum value stored in the ECM is determined
by considering various engine conditions. The EGR volume control
valve remains close under the following conditions.
+Low engine coolant temperature
+Engine starting
+High-speed engine operation
+Extremely light load engine operation
+Engine idling
+Excessively high engine coolant temperature
+Wide open throttle
+Mass air flow sensor malfunction
+Low battery voltage
SEF551W
EGR VOLUME CONTROL SYSTEM (WHERE FITTED)QG
Description
EC-400

DescriptionNJEC1758SYSTEM DESCRIPTIONNJEC1758S01
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS) Engine speed
Idle air
controlIACV-AAC valve Camshaft position sensor (PHASE) Engine speed and cylinder number
Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Throttle position sensor Throttle position
PNP switch Park/Neutral position
Air conditioner switch Air conditioner operation
Power steering oil pressure switch Power steering load signal
Battery Battery voltage
Vehicle speed sensor Vehicle speed
Cooling fan Cooling fan operation
Electrical load Electrical load signal
This system automatically controls engine idle speed to a specified
level. Idle speed is controlled through fine adjustment of the
amount of air which by-passes the throttle valve via IACV-AAC
valve. The IACV-AAC valve changes the opening of the air by-pass
passage to control the amount of auxiliary air. This valve is actu-
ated by a step motor built into the valve, which moves the valve in
the axial direction in steps corresponding to the ECM output sig-
nals. One step of IACV-AAC valve movement causes the respec-
tive opening of the air by-pass passage. (i.e. when the step
advances, the opening is enlarged.) The opening of the valve is
varied to allow for optimum control of the engine idling speed. The
crankshaft position sensor (POS) detects the actual engine speed
and sends a signal to the ECM. The ECM then controls the step
position of the IACV-AAC valve so that engine speed coincides with
the target value memorized in ECM. The target engine speed is the
lowest speed at which the engine can operate steadily. The opti-
mum value stored in the ECM is determined by taking into consid-
eration various engine conditions, such as during warm up,
deceleration, and engine load (air conditioner, power steering, cool-
ing fan operation and electrical load).
SEF937W
COMPONENT DESCRIPTIONNJEC1758S02IACV-AAC ValveNJEC1758S0201The IACV-AAC valve is operated by a step motor for centralized
control of auxiliary air supply. This motor has four winding phases
and is actuated by the output signals of ECM which turns ON and
OFF two windings each in sequence. Each time the IACV-AAC
valve opens or closes to change the auxiliary air quantity, the ECM
sends a pulse signal to the step motor. When no change in the
auxiliary air quantity is needed, the ECM does not issue the pulse
signal. A certain voltage signal is issued so that the valve remains
at that particular opening.
IDLE AIR CONTROL VALVE (IACV) Ð AUXILIARY AIR CONTROL
(AAC) VALVE
QG
Description
EC-418

CONSULT-II Reference Value in Data Monitor
Mode
NJEC0548Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
LOAD SIGNAL+Ignition switch: ONRear window defogger is operating
and/or lighting switch is on.ON
Rear window defogger is not oper-
ating and lighting switch is not on.OFF
HEATER FAN SW+Ignition switch: ONHeater fan motor is operating. ON
Heater fan motor is not operating. OFF
ECM Terminals and Reference ValueNJEC0549Specification 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)
50 L/BElectric load signal
(Load switch)[Engine is running]
+Rear window defogger is operating and/or lighting
switch is onBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
+Rear window defogger is not operating and lighting
switch is not onApproximately 0V
51 LG/B Heater fan motor switch[Engine is running]
+Heater fan motor is operatingApproximately 0V
[Engine is running]
+Heater fan motor is not operatingApproximately 5V
ELECTRICAL LOAD SIGNALQG
CONSULT-II Reference Value in Data Monitor Mode
EC-480

Wiring DiagramNJEC0550
YEC004A
ELECTRICAL LOAD SIGNALQG
Wiring Diagram
EC-481

YEC005A
ELECTRICAL LOAD SIGNALQG
Wiring Diagram (Cont'd)
EC-482

Diagnostic Procedure Ð Load Signal ÐNJEC0584
1 INSPECTION START
Do you have CONSULT-II?
YesorNo
Ye s©GO TO 2.
No©GO TO 4.
2 CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-I
With CONSULT-II
1. Turn ignition switch ªONº.
2. Check ªLOAD SIGNALº in ªDATA MONITORº mode with CONSULT-II under the following conditions.
SEF954X
OK or NG
OK©GO TO 3.
NG©GO TO 6.
3 CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-II
With CONSULT-II
1. Turn ignition switch ªONº.
2. Check ªLOAD SIGNALº in ªDATA MONITORº mode with CONSULT-II under the following conditions.
SEF955X
OK or NG
OK©INSPECTION END
NG©GO TO 9.
ELECTRICAL LOAD SIGNALQG
Diagnostic Procedure Ð Load Signal Ð
EC-483

4 CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-I
Without CONSULT-II
1. Turn ignition switch ªONº.
2. Check voltage between ECM terminal 50 and ground under the following conditions.
SEF956X
OK or NG
OK©GO TO 5.
NG©GO TO 6.
5 CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-II
Without CONSULT-II
1. Turn ignition switch ªONº.
2. Check voltage between ECM terminal 50 and ground under the following conditions.
SEF957X
OK or NG
OK©INSPECTION END
NG©GO TO 10.
6 CHECK REAR WINDOW DEFOGGER FUNCTION
1. Start engine.
2. Turn ªONº the rear window defogger switch.
3. Check the rear windshield. Is the rear windshield heated up?
YesorNo
Ye s©GO TO 7.
No©Refer to EL-138, ªRear Window Defoggerº.
ELECTRICAL LOAD SIGNALQG
Diagnostic Procedure Ð Load Signal Ð (Cont'd)
EC-484

7 CHECK REAR WINDOW DEFOGGER INPUT SIGNAL CIRCUIT
1. Disconnect ECM harness connector.
2. Disconnect time control unit harness connector.
3. Check harness continuity between ECM terminal 50 and time control unit harness connector terminal 14.
Refer to wiring diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK©Refer to EL-229, ªTIME CONTROL UNITº.
NG©GO TO 8.
8 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors M63, F102
+Harness open and short between ECM and time control unit connectors
©Repair open circuit or short to ground or short to power in harness or connectors.
9 CHECK HEADLAMP FUNCTION
1. Start engine.
2. Turn the lighting switch ªONº.
3. Check that headlamps are illuminated.
Do the headlamps illuminate in both ªHighº and ªLowº positions?
YesorNo
Ye s©GO TO 11.
No©Refer to EL-40, ªHEADLAMP SYSTEMº.
10 CHECK HEADLAMP FUNCTION
1. Start engine.
2. Turn the lighting switch ªONº.
3. Check that headlamps are illuminated.
OK or NG
OK©GO TO 11.
NG©Refer to EL-40, ªHEADLAMP SYSTEMº.
ELECTRICAL LOAD SIGNALQG
Diagnostic Procedure Ð Load Signal Ð (Cont'd)
EC-485