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:
P2101 Electric throttle control function
DTC Logic
DTC DETECTION LOGIC
NOTE:
If DTC P2101 is displayed with DTC P2100, first perform the trouble
diagnosis for DTC P2100. Refer
to EC-423, "DTC Logic".
If DTC P2101 is displayed with DTC P2119, first perform the trouble
diagnosis for DTC P2119. Refer
to EC-430, &qu ...
Power supply and ground circuit
Body control system
Body control system : diagnosis procedure
Regarding wiring diagram information, refer to bcs-51, "wiring diagram".
1.Check fuses and fusible link
Check that the following fuses and fusible link are not blown.
Is the fuse blown?
Yes >> replace the blown f ...
P1652 Starter motor system comm
Description
ECM controls ON/OFF state of the starter relay, according to the engine and
vehicle condition. ECM transmits
a control signal to IPDM E/R via BCM by CAN communication.
Under normal conditions, ECM controls and maintains the starter relay in OFF
state during following condition:
...
