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 with motor 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 idle speed (2 trip detection logic).	Electronic throttle control system Intake system PCV hose connection ECM

MONITOR DESCRIPTION

The ECM monitors the idle speed and idling air flow volume to conduct idle speed control. The ECM determines that the idle speed control system is malfunctioning if either of the following conditions is met:

The difference between the target engine idle speed and actual engine idle 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 idle 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

Related DTCs	P0505: Idle air control system functional check
Required Sensors/Components (Main)	Electronic throttle control system
Required Sensors/Components (Related)	Crankshaft position sensor Engine coolant temperature sensor Vehicle speed sensor
Frequency of Operation	Once per driving cycle
Duration	5 seconds
MIL Operation	2 driving cycles
Sequence of Operation	None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever the following DTCs are not stored

P0010, P0020 (Camshaft timing oil control valve bank 1, 2)

P0011, P0021 (VVT system bank 1, 2 - advance)

P0012, P0022 (VVT system bank 1, 2 - retard)

P0013, P0023 (Exhaust camshaft timing oil control valve bank 1, 2)

P0014, P0024 (Exhaust VVT system bank 1, 2 - advance)

P0015, P0025 (Exhaust VVT system bank 1, 2 - retard)

P0016, P0018 (VVT system bank 1, 2 - misalignment)

P0017, P0019 (Exhaust VVT system bank 1, 2 - misalignment)

P0031, P0032, P0051, P0052, P101D, P103D (Air fuel ratio sensor heater)

P0102, P0103 (Mass air flow meter)

P0115, P0117, P0118 (Engine coolant temperature sensor)

P0120, P0121, P0122, P0123, P0220, P0222, P0223, P2135 (Throttle position sensor)

P0125 (Insufficient coolant temperature for closed loop fuel control)

P014C, P014D, P014E, P014F, P015A, P015B, P015C, P015D, P2195, P2196, P2197, P2198, P2237, P2238, P2239, P2240, P2241, P2242, P2252, P2253, P2255, P2256 (Air fuel ratio sensor)

P0171, P0172, P0174, P0175 (Fuel system)

P0300, P0301, P0302, P0303, P0304, P0305, P0306 (Misfire)

P0335 (Crankshaft position sensor)

P0340, P0342, P0343, P0345, P0347, P0348 (VVT sensor)

P0351, P0352, P0353, P0354, P0355, P0356 (Igniter)

P0365, P0367, P0368, P0390, P0392, P0393 (Exhaust VVT sensor)

P0451, P0452, P0453 (EVAP system)

P0500 (Vehicle speed sensor)

P0705 (Shift lever position switch)

P219A, P219B, P219C, P219D, P219E, P219F, P21A0, P21A1 (Air-fuel ratio imbalance)

Engine

Running

TYPICAL MALFUNCTION THRESHOLDS

Either of the following conditions are met	1 or 2
1. Both of the following conditions are met	-
Engine speed - Target engine speed	Less than -100 rpm, or higher than 200 rpm (A/C on or NSW on) Less than -100 rpm, or higher than 150 rpm (A/C off and NSW off)
IAC flow rate learned value	0.88 L/sec. or less, or 8.5 L/sec. or more for 5 seconds or more
2. Both of the following conditions are met	A and B
A. Frequency that both of the following conditions are met	5 times or more
Engine speed - Target engine speed	Less than -100 rpm, or higher than 200 rpm (A/C on or NSW on) Less than -100 rpm, or higher than 150 rpm (A/C off and NSW off)
Vehicle condition	Stopped after vehicle was driven by 10 km/h (6.25 mph) or higher
B. Either of the following condition is met	(a) or (b)
(a) Amount of change of IAC flow rate learning value	+4.04 L/sec. or more, or -7.52 L/sec. or less
(b) IAC flow rate learning value	0.88 L/sec. or less, or 8.5 L/sec. or more

CONFIRMATION DRIVING PATTERN

Connect the Techstream to the DLC3.
Turn the engine switch on (IG) and turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the engine switch off and wait for at least 30 seconds.
Turn the engine switch on (IG) and turn the Techstream 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 / 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 / Utility / All Readiness.
Input the DTC: P0505.

Check the DTC judgment result.

Techstream 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].

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.
Repeat step [E] 5 times.
Enter the following menus: Powertrain / Engine / 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 / Utility / All Readiness.
Input the DTC: P0505.

Check the DTC judgment result.

Techstream 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 is INCOMPLETE or N/A and no pending DTC is output, perform a universal trip and check for permanent DTCs Click here.
Tech Tips
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.

INSPECTION PROCEDURE

Tech Tips

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

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 the Techstream. 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 Techstream to the DLC3.
Turn the engine switch on (IG).
Turn the Techstream on.
Enter the following menus: Powertrain / Engine / 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 from the intake system.
  
  Tech Tips
  
  Perform "Inspection After Repair" after repairing or replacing the intake system Click here.
NG
REPAIR OR REPLACE INTAKE SYSTEM

OK
INSPECT 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.
  
  Tech Tips
  
  Perform "Inspection After Repair" after replacing the throttle with motor body assembly Click here.
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 from the intake system.

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

CHECK WHETHER DTC OUTPUT RECURS (DTC P0505)

Connect the Techstream to the DLC3.
Turn the engine switch on (IG).
Turn the Techstream 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 Techstream on.
Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / 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