2001 NISSAN ALMERA N16 ignition

Diagnostic ProcedureNJEC0278
1 CHECK INPUT SIGNAL CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector and combination meter harness connector.
3. Check harness continuity between ECM terminal 86 and meter terminal 4.
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 3.
NG©GO TO 2.
2 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors M63, F102
+Harness for open or short between ECM and combination meter
©Repair open circuit or short to ground or short to power in harness or connectors.
3 CHECK SPEEDOMETER FUNCTION
Make sure that speedometer functions properly.
OK or NG
OK©GO TO 5.
NG©GO TO 4.
4 CHECK SPEEDOMETER CIRCUIT
Check the following.
+Harness connectors M63, F102
+Harness connectors M169, F113
+Harness for open or short between combination meter and vehicle speed sensor
OK©Check combination meter and vehicle speed sensor. Refer to EL-89, ªMETERS AND
GAUGESº.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
5 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-144.
©INSPECTION END
DTC P0500 VEHICLE SPEED SENSOR (VSS)QG
Diagnostic Procedure
EC-312

DescriptionNJEC0279SYSTEM DESCRIPTIONNJEC0279S01
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 DESCRIPTIONNJEC0279S02IACV-AAC ValveNJEC0279S0202The 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.
DTC P0505 IDLE AIR CONTROL VALVE (IACV) Ð AUXILIARY AIR CONTROL
(AAC) VALVE
QG
Description
EC-313

CONSULT-II Reference Value in Data Monitor
Mode
NJEC0280
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 ValueNJEC0281Specification 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
On Board Diagnosis LogicNJEC0282
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0505
0505+An improper voltage signal is sent to ECM through the
valve.+Harness or connectors
(The IACV-AAC valve circuit is open.)
+IACV-AAC valve
SEF058Y
DTC Confirmation ProcedureNJEC0283NOTE:
+If ªDTC Confirmation Procedureº has been previously
conducted, always turn ignition switch ªOFFº and wait at least
9 seconds before conducting the next test.
+If the target idle speed is out of the specified value, per-
form ªIdle Air Volume Learningº, refer to EC-55, before
conducting ªDTC Confirmation Procedureº. For the target
idle speed, refer to ªSERVICE DATA AND SPECIFICA-
TIONS (SDS)º, EC-489.
With CONSULT-II
1) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Start engine and warm it up to normal operating temperature.
4) Rev engine from idle to 2,000 rpm 20 times.
If 1st trip DTC is detected, go to ªDIAGNOSTIC
PROCEDUREº, EC-297.
With GST
Follow the procedure ªWith CONSULT-IIº above.
DTC P0505 IDLE AIR CONTROL VALVE (IACV) Ð AUXILIARY AIR CONTROL
(AAC) VALVE
QG
CONSULT-II Reference Value in Data Monitor Mode
EC-314

Diagnostic ProcedureNJEC0285
1 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 3.
NG©GO TO 2.
2 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors E75, F36
+Harness for open or short between IACV-AAC and ECM relay
©Repair harness or connectors.
3 CHECK OUTPUT SIGNAL CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector.
3. Check harness continuity between
ECM terminal 6 and terminal 1,
ECM terminal 7 and terminal 4,
ECM terminal 15 and terminal 3,
ECM terminal 16 and 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 4.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
DTC P0505 IDLE AIR CONTROL VALVE (IACV) Ð AUXILIARY AIR CONTROL
(AAC) VALVE
QG
Diagnostic Procedure
EC-316

9 REPLACE IACV-AAC VALVE
1. Replace IACV-AAC valve assembly.
2. Perform ªIdle Air Volume Learningº, EC-55.
Is the result CMPLT or INCMP?
CMPLT or INCMP
CMPLT©INSPECTION END
INCMP©Follow the construction of ªIdle Air Volume Learningº.
10 CHECK TARGET IDLE SPEED
1. Turn ignition switch ªOFFº.
2. Reconnect all harness connectors and vacuum hoses.
3. Start engine and warm it up to normal operating temperature.
4. Also warm up transmission to normal operating temperature.
+For A/T models with CONSULT-II, drive vehicle until ªFLUID TEMP SEº in ªDATA MONITORº mode of ªA/Tº system indi-
cates less than 0.9V.
+For A/T models without CONSULT-II and M/T models, drive vehicle for 10 minutes.
5. Stop vehicle with engine running.
6. Check target idle speed.
M/T: 700±50 rpm
A/T: 800±50 rpm (in ªPº or ªNº position)
OK or NG
OK©GO TO 11.
NG©Perform ªIdle Air Volume Learningº, EC-55.
11 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-144.
©INSPECTION END
DTC P0505 IDLE AIR CONTROL VALVE (IACV) Ð AUXILIARY AIR CONTROL
(AAC) VALVE
QG
Diagnostic Procedure (Cont'd)
EC-319

SEF605Y
SEF089X
Component InspectionNJEC0286IACV-AAC VALVENJEC0286S011) Disconnect IACV-AAC valve harness connector.
2) Check IACV-AAC valve resistance.
Condition Resistance
Terminal 2 and terminals 1, 3
20-24W[at 20ÉC (68ÉF)]
Terminal 5 and terminals 4, 6
3) Reconnect IACV-AAC valve harness connector.
4) Remove idle air adjusting unit assembly (IACV-AAC valve is
built-in) from engine.
(The IACV-AAC valve harness connector should remain con-
nected.)
5) Turn ignition switch ªONº and ªOFFº, and ensure the IACV-
AAC valve shaft smoothly moves forward and backward,
according to the ignition switch position.
If NG, replace the IACV-AAC valve.
DTC P0505 IDLE AIR CONTROL VALVE (IACV) Ð AUXILIARY AIR CONTROL
(AAC) VALVE
QG
Component Inspection
EC-320

SEF505V
Component DescriptionNJEC0287A closed throttle position switch and wide open throttle position
switch are built into the throttle position sensor unit. The wide open
throttle position switch is used only for A/T control.
When the throttle valve is in the closed position, the closed throttle
position switch sends a voltage signal to the ECM. The ECM only
uses this signal to open or close the EVAP canister purge control
valve when the throttle position sensor is malfunctioning.
CONSULT-II Reference Value in Data Monitor
Mode
NJEC0571Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
CLSD THL/P SW+Engine: IdleThrottle valve: Idle position ON
Throttle valve: Slightly open OFF
ECM Terminals and Reference ValueNJEC0288Specification 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)
40 Y/PUThrottle position switch
(Closed position)[Engine is running]
+Accelerator pedal releasedBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
+Accelerator pedal depressedApproximately 0V
On Board Diagnosis LogicNJEC0289
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0510
0510+Battery voltage from the closed throttle position switch is
sent to ECM with the throttle valve opened.+Harness or connectors
(The closed throttle position switch circuit is
shorted.)
+Closed throttle position switch
+Throttle position sensor
SEF197Y
DTC Confirmation ProcedureNJEC0290CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 9 seconds
before conducting the next test.
With CONSULT-II
1) Start engine and warm it up to normal operating temperature.
2) Turn ignition switch ªOFFº, wait at least 9 seconds and then
start engine.
DTC P0510 CLOSED THROTTLE POSITION SWITCH (WHERE FITTED)QG
Component Description
EC-321

Diagnostic ProcedureNJEC0293
1 CHECK POWER SUPPLY
1. Turn ignition switch ªOFFº.
2. Disconnect throttle position switch harness connector.
JEF091Y
3. Turn ignition switch ªONº.
4. Check voltage between terminal 5 and engine ground with CONSULT-II or tester.
SEF837X
Voltage: Battery voltage
OK or NG
OK©GO TO 3.
NG©GO TO 2.
2 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors M169, F113
+10A fuse
+Harness for open or short between throttle position switch and fuse
©Repair harness or connectors.
3 CHECK INPUT SIGNAL CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 40 and terminal 4.
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.
DTC P0510 CLOSED THROTTLE POSITION SWITCH (WHERE FITTED)QG
Diagnostic Procedure
EC-324