P0505

DTC Code	DTC Name
P0505	Idle Control System Malfunction

DESCRIPTION

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

DTC No.	DTC Detection Conditions	Trouble Areas
P0505	Idling speed continues to vary greatly from target idling speed (2 trip detection logic)	Electronic Throttle Control System (ETCS) Air induction system PCV hose connection ECM

DTC No.

DTC Detection Conditions

Trouble Areas

P0505

Idling speed continues to vary greatly from target idling speed

(2 trip detection logic)

Electronic Throttle Control System (ETCS)
Air induction system
PCV 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 conditions are met:

The learned idling air flow volume remains at the maximum or minimum volume 5 times or more during a drive cycle.
While driving at 10 km/h (6 mph) or more, the actual engine idling speed varies from the target idling speed by between 100 rpm and 200 rpm, 5 times or more during a drive cycle.

Example:

If the actual idling speed varies from the target idling speed by more than 200 rpm* 5 times during a driving cycle, the ECM illuminates the MIL and sets the DTC.

*: Threshold idling speed varies with engine load.

INSPECTION PROCEDURE

Tech Tips

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

The floor carpet overlapping slightly 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 an intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

PROCEDURE

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

Connect an intelligent tester to the DLC3.
Turn the ignition switch to the ON position.
Turn the tester ON.
Select the following menu items: Powertrain / Engine and ECT / 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

A

CHECK PCV HOSE

OK

PCV hose is connected correctly and is not damaged.

NG
REPAIR OR REPLACE PCV 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 VALVE
1. Check the throttle valve condition.
NG
REPLACE THROTTLE W/MOTOR BODY ASSEMBLY

OK

REPLACE ECM

SFI SYSTEM (w/ Secondary Air Injection System), Diagnostic DTC:P0505