Nissan Altima 2007-2012 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 CONFIRMATION PROCEDURE


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-566, "IDLE AIR VOLUME LEARNING : Special Repair Requirement", before conducting DTC Confirmation Procedure.

TESTING CONDITION: • Before performing the following procedure, confirm that battery voltage is more than 11V at idle.

• Always perform the test at a temperature above −10В°C(14В°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 EC-855, "Diagnosis Procedure".

NO >> INSPECTION END

Diagnosis Procedure

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.

3. Go to EC-563, "ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT : Special Repair Requirement".

>> INSPECTION END

    P0500 VSS
    Description The vehicle speed signal is sent to the combination meter from the “ABS actuator and electric unit (control unit)” by CAN communication line. The combination meter then sends ...

    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:

    U1000 can comm circuit
    Description CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle multiplex communication line with high data communication speed and excellent malfunction detection ability. Many electronic control units are equipped onto a vehicle, an ...

    Key cylinder switch
    Description For vehicles equipped with LH and RH anti-pinch system, the main power window and door lock/unlock switch detects condition of the door key cylinder switch and transmits to BCM as the LOCK or UNLOCK signal. For vehicles equipped with LH anti-pinch system only, the front door loc ...

    Sound signal circuit (coupe)
    SATELLITE RADIO TUNER Description Left and right channel audio signals are supplied from the satellite radio tuner to the audio unit through the sound signal circuits. Diagnosis Procedure LEFT CHANNEL 1.CHECK HARNESS 1. Turn ignition switch OFF. 2. Disconnect satellite radio tuner (fac ...