P0505

DTC Code	DTC Name
P0505	Idle Control System Malfunction

DESCRIPTION

The idle speed is controlled by the Electronic Throttle Control System (ETCS). The ETCS is comprised of: 1) a one valve type throttle body; 2) the throttle actuator, which operates the throttle valve; 3) the throttle position sensor, which detects the opening angle of the throttle valve; 4) the accelerator pedal position sensor, which detects the accelerator pedal position; 5) the ECM, which controls the ETCS. Based on the target idle speed, the ECM controls the throttle actuator to provide the proper throttle valve opening angle.

DTC No.	DTC Detection Condition	Trouble Area
P0505	Idle speed continues to vary greatly from target speed (2 trip detection logic)	ETCS Air induction system Ventilation hose connection ECM

DTC No.

DTC Detection Condition

Trouble Area

P0505

Idle speed continues to vary greatly from target speed

(2 trip detection logic)

ETCS
Air induction system
Ventilation hose connection
ECM

MONITOR DESCRIPTION

The ECM monitors the idling speed and idling air flow volume to conduct Idle Speed Control (ISC). The ECM determines that the ISC system is malfunctioning if the following condition is met:

After driving at a vehicle speed of 10 km/h (6.25 mph) or more, the difference between the target and actual engine idling speed exceeds the threshold 5 times or more during a driving cycle, and then the system determines that the IAC flow rate learned value is stuck at the upper or lower limit, or that the IAC flow rate learned value has been changed by an amount that exceeds the threshold.

INSPECTION PROCEDURE

Tech Tips

The following conditions may also cause DTC P0505 to be set:

The floor carpet overlapping onto the accelerator pedal, causing the accelerator pedal to be slightly depressed and therefore the throttle valve position to be slightly open.
The accelerator pedal being not fully released.

Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when malfunctions are 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, and other data from the time the malfunction occurred.

PROCEDURE

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0505)

Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG).
Turn the tester ON.
Enter the following menus: Powertrain / Engine / DTC.

Read DTCs.

Result

Display (DTC output)	Proceed to
P0505	A
P0505 and other DTCs	B

Tech Tips

If any DTCs other than P0505 are output, troubleshoot those DTCs first.

B

GO TO DTC CHART Click here

A

CHECK VENTILATION HOSE (HOSE CONNECTIONS)

OK

Ventilation hose is connected correctly and is not damaged.

NG
REPAIR OR REPLACE VENTILATION HOSE

OK
CHECK AIR INDUCTION SYSTEM
1. Check the air induction system for vacuum leakage.
  
  OK
  
  No leakage from air induction system.
NG
REPAIR OR REPLACE AIR INDUCTION SYSTEM

OK
CHECK THROTTLE BODY (VISUALLY CHECK THROTTLE VALVE)
1. Check for contamination between the throttle valve and the housing. If necessary, clean the throttle body. And check that the throttle valve moves smoothly.
  
  OK
  
  Throttle valve is not contaminated with foreign objects and moves smoothly.
NG
REPLACE THROTTLE BODY Click here

OK

REPLACE ECM Click here

SFI SYSTEM, Diagnostic DTC:P0505