Nissan Cube. Manual - part 355
EC-306
< DTC/CIRCUIT DIAGNOSIS >
[MR18DE]
P0506 ISC SYSTEM
P0506 ISC SYSTEM
Description
INFOID:0000000009947421
The ECM controls the engine idle speed to a specified level through the fine adjustment of the air, which is let
into the intake manifold, by operating the electric throttle control actuator. The operating of the throttle 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 controls the electric throttle control actuator so that the engine speed coincides with the target value
memorized in the ECM. The target engine speed is the lowest speed at which the engine can operate steadily.
The optimum value stored in the ECM is determined by taking into consideration various engine conditions,
such as during warming up, deceleration, and engine load (air conditioner and cooling fan operation, etc.).
DTC Logic
INFOID:0000000009947422
DTC DETECTION LOGIC
NOTE:
If DTC P0506 is displayed with other DTC, first perform the trouble diagnosis for the other DTC.
DTC CONFIRMATION PROCEDURE
1.
PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
If the target idle speed is out of the specified value, perform
EC-20, "IDLE AIR VOLUME LEARNING :
, before conducting DTC Confirmation Procedure.
TESTING CONDITION:
• Before performing the following procedure, confirm that battery voltage is more than 11 V at idle.
• Always perform the test at a temperature above
−
10
°
C(14
°
F).
>> GO TO 2.
2.
PERFORM DTC CONFIRMATION PROCEDURE
1.
Start engine and warm it up to normal operating temperature.
2.
Turn ignition switch OFF and wait at least 10 seconds.
3.
Start engine and run it for at least 1 minute at idle speed.
4.
Check 1st trip DTC.
Is 1st trip DTC detected?
YES
>> Go to
NO
>> INSPECTION END
Diagnosis Procedure
INFOID:0000000009947423
1.
CHECK INTAKE AIR LEAK
1.
Start engine and let it idle.
2.
Listen for an intake air leak after the mass air flow sensor.
Is intake air leak detected?
YES
>> Discover air leak location and repair.
NO
>> GO TO 2.
2.
REPLACE ECM
1.
Stop engine.
2.
Replace ECM.
DTC No.
Trouble diagnosis name
DTC detecting condition
Possible cause
P0506
Idle speed control system
RPM lower than expected
The idle speed is less than the target idle
speed by 100 rpm or more.
• Electric throttle control actuator
• Intake air leak