Nissan Sentra Service Manual: 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 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 P0507 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 |
| P0507 | ISC SYSTEM (Idle air control system RPM higher than expected) | The idle speed is more than the target idle speed by 200 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, perform EC-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-336, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis Procedure
1.CHECK PCV HOSE CONNECTION
Confirm that PCV hose is connected correctly.
Is the inspection result normal? YES >> GO TO 2.
NO >> Repair or replace error-detected parts.
2.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".
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 ac ...
P050A, P050B, P050E Cold start control
Description
ECM controls ignition timing and engine idle speed when engine is started
with pre-warming up condition.
This control promotes the activation of three way catalyst by heating the
c ...
Other materials:
Service data and specifications
(sds)
General Specification
Drive Belt
Spark Plug
*:Always check with the Parts Department for the latest parts information.
Exhaust Manifold
Camshaft
VALVE LIFTER
VALVE CLEARANCE
*: Approximately 80В°C (176В°F)
AVAILABLE VALVE LIFTER
*:Always check with the P ...
Ground
Ground distribution
Main harness
Engine room harness
Engine control harness
Body harness
...
P1226 TP Sensor
DTC Logic
DTC DETECTION LOGIC
DTC No.
CONSULT screen terms
(Trouble diagnosis content)
DTC detecting condition
Possible cause
P1226
CTP LEARNING-B1
(CTP LEARNING-B1)
Closed throttle position learning is not performed
successfully, repeatedly.
Electric thr ...
