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.
If the target idle speed is out of the specified value, perform EC-140, "Work Procedure", before conducting DTC Confirmation Procedure.
TESTING CONDITION:
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
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
Is intake air leak detected? YES >> Discover air leak location and repair.
NO >> Replace ECM. Refer to EC-485, "Removal and Installation".
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
catalyst and reduces emissions.
DTC Logic
DTC DETECTION LOGIC
NOTE:
If DTC P050A, P050B or P050E ...
Basic inspection
Diagnosis and repair work flow
Work flow
OVERALL SEQUENCE
DETAILED FLOW
1.GET INFORMATION FOR SYMPTOM
Get detailed information from the customer about the symptom (the
condition and the environment when
the incident/malfunction occurs).
Check operation condition of the function th ...
Automatic speed control device (ASCD)
AUTOMATIC SPEED CONTROL DEVICE (ASCD) : System Description
SYSTEM DIAGRAM
BASIC ASCD SYSTEM
Refer to Owner's Manual for ASCD operating instructions.
Automatic Speed Control Device (ASCD) allows a driver to keep vehicle at
predetermined constant speed
without depressing accelerator pedal ...