Dtc P0505 Idle Control System Malfunction

Engine. Lexus Gs430, Gs300. Uzs190 Grs190
3Gr-Fe Engine Control System. Lexus Gs430, Gs300. Uzs190 Grs190

DESCRIPTION

MONITOR DESCRIPTION

INSPECTION PROCEDURE

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

CHECK PCV HOSE CONNECTIONS

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 Condition
Trouble Area
P0505
Idle speed continues to vary greatly from target speed (2 trip detection logic)
  1. ETCS
  2. Air induction system
  3. PCV hose connection
  4. 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 apply:
HINT:
  1. The learned idling air flow volume remains at the maximum or minimum 5 times or more during a drive cycle
  2. While driving at10 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 drive cycle, the ECM illuminates the MIL and sets the DTC.
HINT:
*: Threshold idling speed varies with engine load.

INSPECTION PROCEDURE

HINT:
  1. The following conditions may also cause DTC P0505 to be set:
    1. 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.
    2. The accelerator pedal being not fully released.
  2. 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)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG).

  1. Turn the tester ON.

  1. Enter the following menus: Powertrain / Engine / DTC.

  1. Read DTCs.

    Result:

    Display (DTC output)
    		Proceed to
    P0505
    		A
    P0505 and other DTCs
    		B
    HINT:
    If any DTCs other than P0505 are output, troubleshoot those DTCs first.


B
GO TO DTC CHART
A


2.CHECK PCV HOSE CONNECTIONS
OK:
PCV hose is connected correctly and is not damaged.


NG
REPAIR OR REPLACE PCV HOSE
OK


3.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


4.CHECK THROTTLE VALVE

  1. Check the throttle valve condition.



NG
REPLACE THROTTLE BODY
OK

REPLACE ECM