Nissan Murano: Dtc/circuit Diagnosis / P0506 Isc System

DTC Description

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 DETECTION LOGIC

The idle speed is less than the target idle speed by 100 rpm or more.

POSSIBLE CAUSE

• Electric throttle control actuator

• Intake air leakage

FAIL-SAFE

Not applicable

CHECK DTC PRIORITY

If DTC P0506 is displayed with other DTC, first perform the trouble diagnosis for the other DTC.

Is applicable DTC detected?

Perform diagnosis of applicable. Refer to DTC Index.

GO TO 2.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following before conducting the next test.

1. Turn ignition switch OFF and wait at least 10 seconds.

2. Turn ignition switch ON.

3. Turn ignition switch OFF and wait at least 10 seconds.

If the target idle speed is out of the specified value, perform Description, 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 3.

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. Turn ignition switch ON.

4. Turn ignition switch OFF and wait at least 10 seconds.

5. Restart engine and run it for at least 1 minute at idle speed.

6. Check 1st trip DTC.

Is 1st trip DTC detected?

Proceed to Diagnosis Procedure

To check malfunction symptom before repair: Refer to Intermittent Incident.

Confirmation after repair: INSPECTION END

CHECK DTC PRIORITY

If DTC P0506 is displayed with other DTC, first perform the trouble diagnosis for the other DTC.

Is applicable DTC detected?

Perform diagnosis of applicable. Refer to DTC Index.

GO TO 2.

CHECK INTAKE AIR LEAKAGE

1. Start engine and let it idle.

2. Listen for an intake air leakage after the mass air flow sensor.

Is intake air leakage detected?

Discover air leakage location and repair.

Replace ECM. Refer to Removal and Installation.