Electric NISSAN ALMERA 2001 Manual PDF

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-511

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-578

Wiring DiagramNJEC0550SEDANNJEC0550S01
HEC892
ELECTRICAL LOAD SIGNALQG
Wiring Diagram
EC-579

HEC893
ELECTRICAL LOAD SIGNALQG
Wiring Diagram (Cont'd)
EC-580

HATCHBACKNJEC0550S03Type-1NJEC0550S0301
HEC819
ELECTRICAL LOAD SIGNALQG
Wiring Diagram (Cont'd)
EC-581

Type-2NJEC0550S0302
HEC966
ELECTRICAL LOAD SIGNALQG
Wiring Diagram (Cont'd)
EC-582

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 14.
ELECTRICAL LOAD SIGNALQG
Diagnostic Procedure Ð Load Signal Ð
EC-583

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 15.
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
Yes (Sedan)©GO TO 7.
Yes (Hatchback)©GO TO 12.
No©Refer to EL-240, ªRear Window Defoggerº.
ELECTRICAL LOAD SIGNALQG
Diagnostic Procedure Ð Load Signal Ð (Cont'd)
EC-584

7 CHECK POWER SUPPLY
1. Stop engine.
2. Turn ªOFFº the rear window defogger switch.
3. Disconnect rear window defogger relay.
4. Check voltage between terminal 3 (LHD models), 5 (RHD models) and ground with CONSULT-II or tester.
SEF626Z
OK or NG
OK©GO TO 8.
NG©Check the following and repair.
+20A fuse
+Harness for open and short between fuse block and rear window defogger relay
8 CHECK REAR WINDOW DEFOGGER RELAY
Refer to ªComponent Inspectionº, EC-590.
OK or NG
OK©GO TO 9.
NG©Replace rear window defogger relay.
9 CHECK REAR WINDOW DEFOGGER INPUT SIGNAL CIRCUIT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 50 and rear window defogger relay terminals 5 (LHD models), 3 (RHD
models).
Refer to wiring diagram.
SEF627Z
3. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 11.
NG©GO TO 10.
ELECTRICAL LOAD SIGNALQG
Diagnostic Procedure Ð Load Signal Ð (Cont'd)
EC-585

16 CHECK HEADLAMP INPUT SIGNAL CIRCUIT-1
1. Stop engine.
2. Disconnect ECM harness connector.
3. Disconnect lighting switch connector.
4. Check harness continuity between ECM terminal 50 and lighting switch connector terminal 10 under the following con-
ditions.
SEF619Y
5. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 18.
NG©GO TO 17.
17 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors M63, F102
+Harness connectors M21, E106
+Joint connector-2
+Harness for open and short between ECM and lighting switch connector
©Repair open circuit or short to ground or short to power in harness or connectors.
18 CHECK HEADLAMP INPUT SIGNAL CIRCUIT-2
1. Stop engine.
2. Disconnect ECM harness connector.
3. Disconnect lighting switch connector.
4. Check harness continuity between ECM terminal 50 and lighting switch connector terminal 9 under the following condi-
tions.
SEF627Y
5. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 22.
NG©GO TO 19.
ELECTRICAL LOAD SIGNALQG
Diagnostic Procedure Ð Load Signal Ð (Cont'd)
EC-587