SFI SYSTEM(w/ EGR System), Diagnostic DTC: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 sensor, which detects the opening angle of the throttle valve; 4) the accelerator pedal position 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.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate	Memory
P0505	Idle Control System Malfunction	Idling speed continues to vary greatly from the target idling speed (2 trip detection logic).	ETCS Air induction system PCV hose connections EGR valve assembly ECM	Comes on	Comes on

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 condition is met:

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)	ETCS
Required Sensors/Components (Related)	Crankshaft position sensor, Engine coolant temperature sensor, and Vehicle speed sensor
Frequency of Operation	Once per driving cycle
MIL Operation	2 driving cycles

TYPICAL MALFUNCTION THRESHOLDS


Both of following conditions A and B met	-
A. 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 150 rpm (A/C off and NSW off) Less than -100 rpm, or more than 200 rpm (A/C on or NSW on)
(b) Vehicle condition	Stopped after being driven at 10 km/h (6.25 mph) or more
B. Either condition is met	(c) or (d)
(c) IAC flow rate learned value	Lower limit or upper limit
(d) Amount of change of IAC flow rate learned value exceeds threshold

CONFIRMATION DRIVING PATTERN

Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG) and turn the tester on.
Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).
Turn the engine switch off and wait for at least 30 seconds.
Turn the engine switch on (IG) and turn the tester 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 1 minute or more [C].

Tip:
In order to keep the idling stable, turn off the A/C and all other electric loads and do not perform any shift operations.
Accelerate the vehicle to 10 km/h (6.25 mph) or more, and then idle the engine for 20 seconds or more [D].

CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
Repeat step [D] 5 times.
Enter the following menus: Powertrain / Engine and ECT / DTC [E].
Read the pending DTCs.
Tip:
- 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.


Tester 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
UNKNOWN	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

Tip:

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 UNKNOWN, perform steps [D] and [E] again.

CAUTION / NOTICE / HINT

Tip:

The following conditions may also cause DTC P0505 to be stored:
1. 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.
2. The accelerator pedal being not fully released.
Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. 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 FOR 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 menus: Powertrain / Engine and ECT / DTC.

Read DTCs.

Powertrain > Engine and ECT > Trouble Codes

Result


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

Tip:

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

B

GO TO DTC CHART

Click here

A

CHECK PCV HOSE CONNECTIONS

Check the PCV hose connections.

Click here

OK

PCV hose is connected correctly and is not damaged.

Result


Result
OK
NG

NG

REPAIR OR REPLACE PCV HOSE

Click here Click here

OK

CHECK AIR INDUCTION SYSTEM

Check the air induction system for vacuum leaks.

Click here Click here

OK

No leaks in air induction system.

Result


Result
OK
NG

NG

REPAIR OR REPLACE AIR INDUCTION SYSTEM

Click here Click here

OK

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE EGR STEP POSITION)

Connect the intelligent tester to the DLC3.
Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
Tip:
- When performing the Active Test, make sure the shift lever is in P or N.
- The A/C switch and all accessory switches should be off.
Turn the tester on.

Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position.

Powertrain > Engine and ECT > Active Test


Tester Display
Control the EGR Step Position

Confirm that Throttle Idle Position is ON and check the engine idling condition and the value of MAP in the Data List while performing the Active Test.

Tip:

Do not leave the EGR valve open for 10 seconds or more during the Active Test.
Be sure to return the EGR valve to step 0 when the Active Test is completed.

OK

MAP and idling condition change in response to EGR step position as follows.

Standard


-	EGR Step Position (Active Test)
-	Step 0	Step 0 to 30
Idling condition	Steady idling	Idling changes from steady to rough idling or engine stalls
MAP (Data List)	20 to 40 kPa (150 to 300 mmHg)	MAP value is at least 10 kPa (75 mmHg) higher than when EGR valve is fully closed

Result


Result
OK
NG

OK

INSPECT THROTTLE BODY ASSEMBLYClick here

NG

INSPECT EGR VALVE ASSEMBLY

Remove the EGR valve assembly.
Click here

Check if the EGR valve is stuck open.

OK

EGR valve is tightly closed.

Result


Result
OK
NG

NG

REPLACE EGR VALVE ASSEMBLY

Click here

OK

INSPECT THROTTLE BODY ASSEMBLY

Check for contamination between the throttle valve and housing, and check that the throttle valve moves smoothly.

OK

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

Result


Result
OK
NG

NG

REPLACE THROTTLE BODY ASSEMBLY

Click here

OK

CONFIRM WHETHER DTC OUTPUT RECURS

Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG).
Turn the tester on.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

Read the DTCs.

Powertrain > Engine and ECT > Trouble Codes

Result


Result	Proceed to
P0505 is output	A
No DTC is output	B

A

REPLACE ECM

Click here

B

END