P0505

DTC Code	DTC Name
P0505	Idle Control System Malfunction

DESCRIPTION

The idle speed is controlled by the electronic throttle control system. The electronic throttle control system is comprised of: 1) one valve type throttle body assembly; 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 electronic throttle control system. 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)	Electronic throttle control system Intake 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 either of the following conditions is met:

The difference between the target engine idling speed and actual engine idling speed exceeds the threshold and the IAC flow rate learned value is stuck at the upper or lower limit for 5 seconds or more.
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.

MONITOR STRATEGY

Required Sensors/Components (Main)	Electronic throttle control system
Required Sensors/Components (Related)	Crankshaft position sensor, engine coolant temperature sensor, and vehicle speed sensor
Frequency of Operation	Once per driving cycles
MIL Operation	2 driving cycles

TYPICAL MALFUNCTION THRESHOLDS

Either condition is met	1 or 2
1. Both of following conditions A and B met	-
A. Engine speed - Target engine speed	Less than -100 rpm, or more than 200 rpm (A/C off and shift position is not neutral) Less than -100 rpm, or more than 200 rpm (A/C on or shift position is neutral)
B. IAC flow rate learned value	1.22 L/sec. or less, or 7.8 L/sec. or more for 5 seconds or more
2. Both of following conditions C and D met	-
C. Frequency that both of following conditions (a) and (b) met	5 times or more
(a) Engine speed - Target engine speed	Less than -100 rpm, or more than 200 rpm (A/C off and shift position is not neutral) Less than -100 rpm, or more than 200 rpm (A/C on or shift position is neutral)
(b) Vehicle condition	Stopped after vehicle was driven by 10 km/h (6.25 mph) or more
D. Either condition is met	(c) or (d)
(c) Amount of change of IAC flow rate learning value	+1.93 L/sec. or more, or -3.62 L/sec. or less
(d) IAC flow rate learned value	1.22 L/sec. or less, or 7.8 L/sec. or more

CONFIRMATION DRIVING PATTERN

Connect the GTS to the DLC3.
Turn the engine switch on (IG) and turn the GTS on.
Clear DTCs (even if no DTCs are stored, perform the clear DTC operation) Click here.
Turn the engine switch off and wait for at least 30 seconds.
Turn the engine switch on (IG) and turn the GTS on [A].
Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher with all the accessories switched off [B].
Idle the engine for 5 minutes or more [C].

Tech Tips

In order to keep the idling stable, turn off the A/C and all other electric loads and do not perform any shift operations.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [D].
Read the pending DTCs.
Tech Tips
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.
Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Input the DTC: P0505.

Check the DTC judgment result.

GTS Display	Description
NORMAL	DTC judgment completed System normal
ABNORMAL	DTC judgment completed System abnormal
INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

Tech Tips

If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.
If the judgment result shows INCOMPLETE or N/A, perform steps [E] and [F].

Accelerate the vehicle to 10 km/h (6.25 mph) or more, and then idle the engine for 20 seconds or more [E].
Repeat step [E] 5 times.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [F].
Read the pending DTCs.
Tech Tips
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.
Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Input the DTC: P0505.

Check the DTC judgment result.

GTS Display	Description
NORMAL	DTC judgment completed System normal
ABNORMAL	DTC judgment completed System abnormal
INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

Tech Tips

If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.

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 GTS. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, 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.
Refer to "Data List / Active Test" [Engine Speed, ISC Feedback Value and ISC Learning Value] Click here.

PROCEDURE

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

Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

Read the DTCs.

Result

Result	Proceed to
DTC P0505 is output	A
DTC P0505 and other DTCs are output	B

Tech Tips

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

B

GO TO DTC CHART Click here

A

CHECK PCV HOSE CONNECTIONS
1. Check the PCV hose connections Click here.
  
  OK
  
  PCV valve and hose are connected correctly and are not damaged.
NG
REPAIR OR REPLACE PCV HOSE

OK
CHECK INTAKE SYSTEM
1. Check the intake system for vacuum leaks Click here.
  
  OK
  
  No leaks in the intake system.
NG
REPAIR OR REPLACE INTAKE SYSTEM

OK
CHECK THROTTLE WITH MOTOR BODY ASSEMBLY (THROTTLE VALVE)
1. Check the throttle with motor body assembly condition.
  
  OK
  
  Throttle valve is not contaminated with foreign objects and moves smoothly.
NG
REPLACE THROTTLE WITH MOTOR BODY ASSEMBLY Click here

OK

OK
PCV valve and hose are connected correctly and are not damaged.

OK
No leaks in the intake system.

OK
Throttle valve is not contaminated with foreign objects and moves smoothly.

CHECK WHETHER DTC OUTPUT RECURS (DTC P0505)

Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Clear the DTCs Click here.
Turn the engine switch off and wait for at least 30 seconds.
Turn the engine switch on (IG).
Turn the GTS on.
Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

Read the pending DTCs.

Result

Result	Proceed to
DTC P0505 is output	A
DTC is not output	B

B

END

A

REPLACE ECM Click here

SFI SYSTEM, Diagnostic DTC:P0505