Nissan Sentra Service Manual: P0506 ISC System
Description
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, power steering and cooling fan operation, etc.).
DTC Logic
DTC DETECTION LOGIC
NOTE:
If DTC P0506 is displayed with other DTC, first perform the trouble diagnosis for the other DTC.
| DTC No. | CONSULT screen terms (Trouble diagnosis content) | DTC detecting condition | Possible cause |
| P0506 | ISC SYSTEM (Idle air control system RPM lower than expected) | The idle speed is less than the target idle speed by 100 rpm or more. |
|
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
- Turn ignition switch OFF and wait at least 10 seconds.
- Turn ignition switch ON.
- Turn ignition switch OFF and wait at least 10 seconds.
If the target idle speed is out of the specified value, performEC-140, "Work Procedure", 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 −10В°C (14В°F).
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
- Start engine and warm it up to normal operating temperature.
- Turn ignition switch OFF and wait at least 10 seconds.
- Start engine and run it for at least 1 minute at idle speed.
- Check 1st trip DTC.
Is 1st trip DTC detected? YES >> Proceed to EC-334, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis Procedure
1.CHECK INTAKE AIR LEAK
- Start engine and let it idle.
- 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 >> Replace ECM. Refer to EC-485, "Removal and Installation".
P0500 VSS
EXCEPT FOR M/T MODELS
EXCEPT FOR M/T MODELS : Description
ECM receives vehicle speed signals from two different paths via CAN
communication line: One is from the
ABS actuator and electric unit (c ...
P0507 ISC System
Description
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 ac ...
Other materials:
Checking engine oil level
Park the vehicle on a level surface and apply
the parking brake.
Start the engine and let it idle until it reaches
operating temperature.
Turn off the engine. Wait more than
10 minutes for the oil to drain back into
the oil pan.
Remove the dipstick and wipe it clean. Reinsert
...
Additional service when replacing ecm
Description
When replacing ECM, the following procedure must be performed. (For details,
refer to EC-135, "Work Procedure".)
PROGRAMMING OPERATION
NOTE:
After replacing with a blank ECM, programming is required to write ECM
information. Be sure to follow the procedure
to perform t ...
Front disc brake
Brake Burnishing
CAUTION:
Burnish contact surfaces between brake pads and disc rotor
according to the following procedure
after refinishing the disc rotor, replacing brake pads or if a soft pedal
occurs at very low mileage.
Be careful of vehicle speed. Brakes do not operate firmly/sec ...