P0505

DTC P0505 IDLE AIR CONTROL SYSTEM

CIRCUIT DESCRIPTION

DTC Detecting Condition:

The rotary solenoid type idle air control (IAC) valve is located under the throttle body and intake air bypassing the throttle valve flows into the IAC valve through the passage.

In this way, the intake air volume bypassing the throttle valve is regulated, controlling the engine speed.

The ECM operates the IAC valve only to perform idle-up and provide feedback for the target idling speed.

MONITOR DESCRIPTION

Monitor Strategy:

Typical Enabling Conditions:

Typical Malfunction Thresholds:

Component Operating Range:

The idle speed is controlled by the Electronic Throttle Control System (ETCS).

The ETCS is composed of the throttle motor, which operates the throttle valve, and the throttle position sensor, which detects the opening angle of the throttle valve.

The ECM controls the throttle motor to provide the proper throttle valve opening angle to obtain the target idle speed.

The ECM regulates the idle speed by opening and closing the throttle valve using the ETCS. The ECM concludes that the idle speed control ECM function is malfunctioning if: 1) the actual idle RPM varies more than the specified amount, or 2) a learning value of the idle speed control remains at the maximum or minimum five times or more during a driving cycle. The ECM will turn on the MIL and set a DTC.

Example:
If the RPM difference between the target and actual idle engine RPM exceeds 200 rpm (*1) with the vehicle stopped with idling, and this occurs 5 times, or if the learning value angle of the IAC remains at its maximum or minimum angle for 5 seconds, P0505 is detected. P0511 is detected as an open or short in the IAC circuit if the rate of duty signal input to the IAC valve stuck at 0 or 100%.

HINT: *1: RPM threshold varies with engine load.

Wiring Diagram:

INSPECTION PROCEDURE

HINT:
- When the throttle position is slightly opened (the accelerator pedal is slightly depressed) because floor carpet is overlapped on the accelerator pedal, or if not fully releasing the accelerator pedal, etc.,DTC P505 will possibly be detected.
- Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, as well as other data from the time when a malfunction occurred.

Step 1 - 3:

Step 4 - 6:

Step 7 - 9:

Hand-held tester

Step 1 - 4:

Step 5 - 7:

OBD II scan tool (excluding hand-held tester)

CHECK FOR INTERMITTENT PROBLEMS

Hand-held tester only:
Inspect the vehicle's ECM using check mode. Intermittent problems are easier to detect when the ECM is in check mode with hand-held tester. In check mode, the ECM uses 1 trip detection logic, which has a higher sensitivity to malfunctions than normal mode (default), which uses 2 trip detection logic.

a. Clear the DTCs.
b. Set the check mode.
c. Perform a simulation test.
d. Check the connector and terminal.
e. Wiggle the harness and connector.