NISSAN ALMERA 2001 Service Manual

Diagnostic ProcedureNJEC1756
1 INSPECTION START
Do you have CONSULT-II?
YesorNo
Ye s©GO TO 2.
No©GO TO 3.
2 CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE CONTROL FUNCTION
With CONSULT-II
1. Turn ignition switch ªOFFº.
2. Disconnect the EVAP purge hose connected to the EVAP canister purge volume control solenoid valve at the EVAP
canister.
3. Turn ignition switch ªONº and select ªPURG VOL CONT/Vº in ªACTIVE TESTº mode with CONSULT-II.
4. Start engine and let it idle.
5. Change the valve opening percentage touching ªQuº and ªQdº and check for vacuum existence under the following
conditions.
SEC582C
OK or NG
OK©GO TO 4.
NG©GO TO 5.
EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVEQG
Diagnostic Procedure
EC-507

3 CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE CONTROL FUNCTION
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch ªOFFº.
3. Disconnect the EVAP purge hose connected to the EVAP canister purge volume control solenoid valve at the EVAP
canister.
4. Start engine and let it idle for at least 90 seconds.
5. Check for vacuum existence at the EVAP purge hose under the following conditions.
SEF760Z
OK or NG
OK©GO TO 4.
NG©GO TO 5.
4 CHECK EVAP CANISTER
1. Turn ignition switch ªOFFº.
2. Remove EVAP canister.
3. Block port B of EVAP canister.
4. Blow air through port A orally, and confirm that air flows freely through port C with check valve resistance.
5. Block port A of EVAP canister.
6. Blow air through port B orally, and confirm that air flows freely through port C.
SEF917W
OK or NG
OK©INSPECTION END
NG©Replace EVAP canister.
EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVEQG
Diagnostic Procedure (Cont'd)
EC-508

5 CHECK POWER SUPPLY
1. Turn ignition switch ªOFFº.
2. Disconnect EVAP canister purge volume control solenoid valve harness connector.
SEF076X
3. Turn ignition switch ªONº.
4. Check voltage between terminals 1 and engine ground with CONSULT-II or tester.
SEF606Y
OK or NG
OK©GO TO 7.
NG©GO TO 6.
6 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors E74, F35 (If so equipped)
+Harness connectors M169, F113 (If so equipped)
+10A fuse
+Harness for open or short between EVAP canister purge volume control solenoid valve and fuse
©Repair harness or connectors.
7 CHECK OUTPUT SIGNAL CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 14 and terminal 2.
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 8.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVEQG
Diagnostic Procedure (Cont'd)
EC-509

8 CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Refer to ªComponent Inspectionº, EC-510.
OK or NG
OK©GO TO 9.
NG©Replace EVAP canister purge volume control solenoid valve.
9 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-177.
©INSPECTION END
SEF801Y
SEF661U
Component InspectionNJEC1757EVAP CANISTER PURGE VOLUME CONTROL
SOLENOID VALVE
NJEC1757S01With CONSULT-II
1) Start engine.
2) Perform ªPURG VOL CONT/Vº in ªACTIVE TESTº mode with
CONSULT-II. Check that engine speed varies according to the
valve opening.
If OK, inspection end. If NG, go to following step.
3) Check air passage continuity.
Condition
PURG VOL CONT/V valueAir passage continuity
between A and B
100.0% Yes
0.0% No
If NG, replace the EVAP canister purge volume control sole-
noid valve.
Without CONSULT-II
Check air passage continuity.
ConditionAir passage continuity
between A and B
12V direct current supply between ter-
minalsYe s
No supply No
If NG, replace the EVAP canister purge volume control solenoid
valve.
EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVEQG
Diagnostic Procedure (Cont'd)
EC-510

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
NJEC1759
MONITOR ITEM CONDITION SPECIFICATION
IACV-AAC/V+Engine: After warming up
+Air conditioner switch: OFF
+Shift lever: ªNº
+No-loadIdle 5 - 25 steps
2,000 rpm Ð
ECM Terminals and Reference ValueNJEC1760Specification 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)
6
7
15
16BR
LG
P
ORIACV-AAC valve[Engine is running]
+Warm-up condition
+Idle speed0.1 - 14V
IDLE AIR CONTROL VALVE (IACV) Ð AUXILIARY AIR CONTROL
(AAC) VALVE
QG
CONSULT-II Reference Value in Data Monitor Mode
EC-512

Wiring DiagramNJEC1761SEDAN MODELS AND HATCHBACK MODELS WITH ECM IN ENGINE COMPARTMENTNJEC1761S01
HEC910
IDLE AIR CONTROL VALVE (IACV) Ð AUXILIARY AIR CONTROL
(AAC) VALVE
QG
Wiring Diagram
EC-513

HATCHBACK MODELS WITH ECM IN CABINNJEC1761S02
HEC982
IDLE AIR CONTROL VALVE (IACV) Ð AUXILIARY AIR CONTROL
(AAC) VALVE
QG
Wiring Diagram (Cont'd)
EC-514

Diagnostic ProcedureNJEC1762
1 CHECK OVERALL FUNCTION
1. Turn ignition switch ªOFFº.
2. Read the voltage signal between ECM terminals 6, 7, 15, 16 (IACV-AAC valve signal) and ground with an oscilloscope.
3. Turn ignition switch ªONº, wait at least 5 seconds and then ªOFFº.
4. Verify that the oscilloscope screen shows the signal wave as shown below at least once every 10 seconds after turning
ignition switch ªOFFº.
SEF756Z
OK or NG
OK©INSPECTION END
NG©GO TO 2.
2 CHECK POWER SUPPLY
1. Turn ignition switch ªOFFº.
2. Disconnect IACV-AAC valve harness connector.
NEF316A
3. Turn ignition switch ªONº.
4. Check voltage between terminal 2, 5 and ground with CONSULT-II or tester.
SEF343X
OK or NG
OK©GO TO 4.
NG©GO TO 3.
IDLE AIR CONTROL VALVE (IACV) Ð AUXILIARY AIR CONTROL
(AAC) VALVE
QG
Diagnostic Procedure
EC-515

3 DETECT MALFUNCTIONING PART
Check the following.
+15A fuse
+Harness connectors E75, F36 (If so equipped)
+Harness for open or short between fuse and ECM relay
+ECM relay
+Harness for open or short between IACV-AAC and ECM relay.
©Repair harness or connectors, or replace fuse or ECM relay.
4 CHECK OUTPUT SIGNAL CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector.
3. Check harness continuity between
ECM terminal 6 and IACV-AAC valve terminal 1,
ECM terminal 7 and IACV-AAC valve terminal 4,
ECM terminal 15 and IACV-AAC valve terminal 3,
ECM terminal 16 and IACV-AAC valve terminal 6.
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©Repair open circuit or short to ground or short to power in harness or connectors.
5 CHECK AIR CONTROL VALVE (POWER STEERING) OPERATION-I
1. Reconnect the ECM harness connector and IACV-AAC valve harness connector.
2. Disconnect the vacuum hose connected to the air control valve (Power steering) at the intake air duct.
3. Start engine and let it idle.
4. Check vacuum hose for vacuum existence.
SEF162Z
Vacuum does not exist or slightly exist.
OK or NG
OK©GO TO 6.
NG©Replace air control valve (Power steering).
IDLE AIR CONTROL VALVE (IACV) Ð AUXILIARY AIR CONTROL
(AAC) VALVE
QG
Diagnostic Procedure (Cont'd)
EC-516