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 Description
DTC DETECTION LOGIC
DTC No. | CONSULT screen terms (Trouble diagnosis content) | DTC detecting condition |
P050 | 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. |
POSSIBLE CAUSE
FAIL-SAFE
Not applicable
DTC CONFIRMATION PROCEDURE
1.CHECK DTC PRIORITY
If DTC P0506 is displayed with other DTC, first perform the trouble diagnosis for other DTC.
Is applicable DTC detected? YES >> Perform diagnosis of applicable. Refer to EC-93, "DTC Index".
NO >> GO TO 2.
2.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
If the target idle speed is out of the specified value, perform EC-141, "Work Procedure", before conducting DTC Confirmation Procedure.
TESTING CONDITION:
>> GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE
Is 1st trip DTC detected? YES >> Proceed to EC-353, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis Procedure
1.CHECK DTC PRIORITY
If DTC P0506 is displayed with other DTC, first perform the trouble diagnosis for other DTC.
Is applicable DTC detected? YES >> Perform diagnosis of applicable. Refer to EC-93, "DTC Index".
NO >> GO TO 2.
2.CHECK INTAKE AIR LEAK
Is intake air leak detected? YES >> Discover air leak location and repair.
NO >> Replace ECM. Refer to EC-499, "Removal and Installation".
C1735 ignition signal
DTC Logic
NOTE:
The Signal Tech II Tool [- (J-50190)] can be used to perform the following
functions. Refer to the Signal Tech II
User Guide for additional information.
Activate and display TPMS sensor IDs
Display tire pressure reported by the TPMS sensor
Read TPMS DTC ...
How to erase permanent DTC
Description
OUTLINE
When a DTC is stored in ECM
When a DTC is stored in ECM and MIL is ON, a permanent DTC is erased with MIL
shutoff if the same malfunction
is not detected after performing the driving pattern for MIL shutoff three times
in a raw.
*1: When the same malfunction is detecte ...
Structure and operation
Positive Crankcase Ventilation
This system returns blow-by gas to the intake manifold.
The positive crankcase ventilation (PCV) valve is provided to conduct crankcase
blow-by gas to the intake
manifold.
During partial throttle operation of the engine, the intake manifold sucks the
bl ...