P0505

System/Wiring Diagram:

CIRCUIT DESCRIPTION
This system controls the bypass air flow by means of ECM (PCM) and idle air control valve (IAC valve) for the following four purposes.
- To keep the engine idle speed as specified at all times.
The engine idle speed can vary due to following reasons.
- Load applied to engine (when electric load is applied, automatic transmission is shifted to "R", "D", "2" or "L" range, A/C is turned ON, etc.)
- Variation in atmospheric pressure
- Change in engine itself with passage of time
- Other factors causing idle speed to change

- To improve starting performance of engine
- To compensate air/fuel mixture ratio when decelerating (Dash-pot effect)
- To improve driveability when while engine is warmed up.




OPERATION
IAC valve operates according to signal sent from ECM (PCM). ECM (PCM) detects the engine and vehicle conditions by using the signals from various sensors and switches and control the bypass air flow by changing IAC valve opening.

When the vehicle is at a stop, the throttle valve is at closed position and the engine is running, the engine speed is kept at a specified idle speed.

M/T Vehicle:

A/T Vehicle:

Engine idle speed specification:

DTC Detecting Condition And Trouble Area:

DTC CONFIRMATION PROCEDURE

NOTE: Check to make sure that following condition is satisfied when using this "DTC CONFIRMATION PROCEDURE".
- Intake air temp.: -8 °C (18 °F) or higher
- Engine coolant temp.: - 8 - 110 °C (18 - 230 °F)
- Altitude (barometric pressure) : 2400 m, 8000 ft or less (560 mmHg (75 kPa) or more)

1. Connect scan tool to DLC with ignition switch OFF.
2. Turn ON ignition switch and clear DTC, pending DTC and freeze frame data by using scan tool and warm up engine completely.
3. Run engine at idle speed for 1 min.
4. Check pending DTC by using scan tool.

Step 1 - 5:

Step 6:

TROUBLESHOOTING