Dtc P0505 Idle Control System Malfunction

Lexus IS250 IS220d GSE20 ALE20 4GR-FSE ENGINE CONTROL SYSTEM

DESCRIPTION

INSPECTION PROCEDURE

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

CHECK PCV HOSE (HOSE CONNECTION)

CHECK AIR INDUCTION SYSTEM

CHECK THROTTLE VALVE

DTC 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 ConditionTrouble Area
P0505Idle speed continues to vary greatly from target speed (2 trip detection logic)
ETCS
Air induction system
PCV hose connection
ECM

INSPECTION PROCEDURE

  • HINT:
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 .
1.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 the menus: Power train / Engine / DTC.

Read DTCs.

  • Result:
  • Display (DTC output)Proceed to
    Only P0505A
    P0505 and other DTCsB
  • HINT:
  • If any DTCs other than P0505 are output, troubleshoot those DTCs first.
B
GO TO DTC CHART
A
2.CHECK PCV HOSE (HOSE CONNECTION)
  • OK:
  • PCV hose is connected correctly and is not damaged.
NG
REPAIR OR REPLACE PCV HOSE
OK
3.CHECK AIR INDUCTION SYSTEM

Check the air induction system for vacuum leakage.

  • OK:
  • No leakage from air induction system.
NG
REPAIR OR REPLACE AIR INDUCTION SYSTEM
OK
4.CHECK THROTTLE VALVE

Check the throttle valve condition.

NG
REPLACE THROTTLE BODY
OK
REPLACE ECM