Infiniti G20 (P11). Manual — part 256
Diagnostic Procedure
NCEC0278
1
CHECK INPUT SIGNAL CIRCUIT
1. Turn ignition switch “OFF”.
2. Disconnect ECM harness connector and combination meter harness connector.
3. Check harness continuity between ECM terminal 86 and combination meter terminal 13.
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.
I
Harness connectors F23, M49
I
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 FOR OPEN AND SHORT
Check the following.
I
Harness connectors M6, E75
I
Harness connectors E33, E101
I
Harness for open or short between combination meter and vehicle speed sensor
OK or NG
OK
©
Check combination meter and vehicle speed sensor. Refer to EL-84, “METERS AND
GAUGES”.
NG
©
Repair open circuit or short to ground or short to power in harness or connectors.
5
CHECK INTERMITTENT INCIDENT
Perform “TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT”, EC-146.
©
INSPECTION END
GI
MA
EM
LC
FE
CL
MT
AT
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0500 VEHICLE SPEED SENSOR (VSS)
Diagnostic Procedure
EC-435
Description
NCEC0279
SYSTEM DESCRIPTION
NCEC0279S01
Sensor
Input Signal to ECM
ECM func-
tion
Actuator
Camshaft position sensor
Engine speed
Idle air
control
IACV-AAC valve
Mass air flow sensor
Amount of intake air
Engine coolant temperature sensor
Engine coolant temperature
Ignition switch
Start signal
Throttle position sensor
Throttle position
Park/neutral 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
Intake air temperature sensor
Intake air temperature
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
camshaft position sensor detects the actual engine speed and
sends a signal to the ECM. The ECM then controls the step posi-
tion 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 takig into consid-
eration various engine conditions, such as during warm up,
deceleration, and engine load (air conditioner, power steering and
cooling fan operation).
SEF937W
COMPONENT DESCRIPTION
NCEC0279S02
IACV-AAC Valve
NCEC0279S0202
The 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 seqeunce. Each time the IACV-AAC
valve opens or closes to change tha 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) — AUXILIARY AIR CONTROL
(AAC) VALVE
Description
EC-436
CONSULT-II Reference Value in Data Monitor
Mode
NCEC0280
MONITOR ITEM
CONDITION
SPECIFICATION
IACV-AAC/V
I
Engine: After warming up
I
Air conditioner switch: OFF
I
Shift lever: “N”
I
No-load
Idle
5 - 20 steps
2,000 rpm
—
ECM Terminals and Reference Value
NCEC0281
Specification 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.
TERMI-
NAL
NO.
WIRE
COLOR
ITEM
CONDITION
DATA (DC Voltage)
6
7
15
16
BR
L
R
G
IACV-AAC valve
[Engine is running]
I
Idle speed
0.1 - 14V
On Board Diagnosis Logic
NCEC0282
DTC No.
Malfunction is detected when ...
Check Items (Possible Cause)
P0505
A)
The IACV-AAC valve does not operate properly.
I
Harness or connectors
(The IACV-AAC valve circuit is open.)
I
IACV-AAC valve
B)
The IACV-AAC valve does not operate properly.
I
Harness or connectors
(The IACV-AAC valve circuit is shorted.)
I
Air control valve (Power steering)
I
IACV-AAC valve
I
Intake air leak
I
PCV system
DTC Confirmation Procedure
NCEC0283
NOTE:
I
If
“DTC
Confirmation
Procedure”
has
been
previously
conducted, always turn ignition switch “OFF” and wait at least
10 seconds before conducting the next test.
I
Perform “Procedure for malfunction A” first. If 1st trip DTC
cannot be confirmed, perform “Procedure for malfunction
B”.
I
If the target idle speed is out of the specified value, per-
form “Idle Air Volume Learning”, EC-65, before conducting
“DTC Confirmation Procedure”. For the target idle speed,
GI
MA
EM
LC
FE
CL
MT
AT
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0505 IDLE AIR CONTROL VALVE (IACV) — AUXILIARY AIR CONTROL
(AAC) VALVE
CONSULT-II Reference Value in Data Monitor Mode
EC-437
refer to the “Service Data and Specifications (SDS)”,
EC-632.
SEF058Y
PROCEDURE FOR MALFUNCTION A
NCEC0283S01
TESTING CONDITION:
Before performing the following procedure, confirm that bat-
tery voltage is more than 10.5V with ignition switch “ON”.
With CONSULT-II
1)
Turn ignition switch “ON”.
2)
Select “DATA MONITOR” mode with CONSULT-II.
3)
Start engine and let it idle.
4)
Keep engine speed at 2,500 rpm for three seconds, then let it
idle for three seconds.
5)
Perform step 4 once more.
6)
If 1st trip DTC is detected, go to “Diagnostic Procedure”,
EC-440.
With GST
Follow the procedure “With CONSULT-II” above.
SEF174Y
PROCEDURE FOR MALFUNCTION B
NCEC0283S02
TESTING CONDITION:
I
Before performing the following procedure, make sure
battery voltage is more than 11V at idle.
I
Always perform the test at a temperature above –10°C
(14°F).
With CONSULT-II
1)
Open engine hood.
2)
Start engine and warm it up to normal operating temperature.
3)
Turn ignition switch “OFF” and wait at least 10 seconds.
4)
Turn ignition switch “ON” again and select “DATA MONITOR”
mode with CONSULT-II.
5)
Start engine and run it for at least 1 minute at idle speed.
6)
If 1st trip DTC is detected, go to “Diagnostic Procedure”,
EC-440.
With GST
Follow the procedure “With CONSULT-II” above.
DTC P0505 IDLE AIR CONTROL VALVE (IACV) — AUXILIARY AIR CONTROL
(AAC) VALVE
DTC Confirmation Procedure (Cont’d)
EC-438
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст