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COMPONENT LOCATION

GENERAL DESCRIPTION

When the TP sensor’s signal indicates closed throttle position and the engine is idling, the ECM adjusts the idle speed control actuator so that the engine runs at the correct idling speed, regardless of coolant temperature, load and etc. When the additional load applied in the engine, the air flow through the idle speed control actuator is increased momentarily to raise the idling speed.

DTC DESCRIPTION

The ECM monitors engine speed deviation from the target idle engine speed when the vehicle is stopped and the throttle valve opening is stable. The ECM sets DTC P0506 if the difference to the target idle engine speed is lower than the predetermined threshold.

DTC DETECTING CONDITION

Item	Detecting Condition	Possible Cause
DTC Strategy	● Monitor deviation between target idle speed and actual engine speed	● Restriction in intake or exhaust system ● Carbonustment of the accelerator cable ● Contact resistance in connectors ● Faulty ICA valve
Enable Conditions	● Coolant temperature ＞73℃(163.4℉) ● Throttle angle: closed ● Vehicle speed = 0 ● 10seconds after engine start. ● 10V＜ Battery voltage ＜16 ● No relevant failure
Threshold Value	● Engine speed-Target idle speed ＜ -100rpm (Engine speed too low)
Diagnostic Time	● 16 seconds
MIL On Condition	● 2 Driving Cycles

SIGNAL WAVEFORM AND DATA

MONITOR DTC STATUS

note

If any MAFS or ISCA codes are present, do ALL REPAIRS associated with them before proceeding with this troubleshooting tree.

Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode

Press F4(DTAL) to select DTC information from the DTCs menu

Confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions

Read "DTC Status" parameter

Is parameter displayed "History(Not Present) fault"?

note

History (Not Present) fault : DTC occurred but has been cleared.

Present fault : DTC is occurring at present time.

▶ Fault is intermittent caused by poor contact in the sensor's and/or ECM's connector or was repaired and ECM memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.

▶ Go to next step as below

Check for restricted intake or exhaust system

Visually/physically inspect the following items:

Air cleaner filter element for excessive dirt or for any foreign objects

Throttle body inlet for damage or for any foreign objects

Restricted exhaust system

Was a problem found in any of the above areas?

▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure

▶ Go to next step as below

TERMINAL AND CONNECTOR INSPECTION

Many malfunctions in the electrical system are caused by poor harness(es) and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.

Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.

Has a problem been found?

▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure

▶ Go to next step as below

COMPONENT INSPECTION

ISCA Inspection

Ignition "OFF".

Remove ISCA from Throttle body and Check for throttle bore, throttle plate and the ISCA passages for chocking and for any foreign objects. Repair or clean as necessary.

Ignition "ON" ＆ Engine "OFF".

Connect scan tool and select "IDLE SPEED ACTUATOR" parameter on the "ACTUATION TEST" mode.

Activates ISCA by pressing "STAT" key.

Check the ISCA for clicking sound and visually verifying valve closes and opens.

note

Repeat numerous times to ensure valve reliability.

Is ISCA Valve moving freely and not carbon fouled?

▶ Check for poor connection between ECM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection. Repair as necessary and go to "Verification of Vehicle Repair" procedure

▶ Check ISCA valve for contamination, deterioration, or damage. Substitute with a known-good ISCA valve and check for proper operation. If the problem is corrected, replace ISCA valve and then go to "Verification of Vehicle Repair" procedure

VERIFICATION OF VEHICLE REPAIR

After a repair, it is essential to verify that the fault has been corrected.

Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.

Press F4(DTAL) and confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions.

Read "DTC Status" parameter.

Is parameter displayed "History(Not Present) fault"?

▶ System performing to specification at this time. Clear the DTC

▶ Go to the applicable troubleshooting procedure.