3.
Monitor items which affect idle rpm on scantool.
The IAC System is designed to maintain a steady desired idle speed. Idle airflow is adjustedthrough the idle air actuator, which may be ETC throttle body, in order to maintain the desired idle speed under various load conditions. Load conditions vary due to numerous factors, such as engine temperature, air conditioning, electrical load and power steering load.
Checking idle RPM from under detecting condition, if the idle speed is more than 200 RPM above desired idle speed, PCM sets P0507. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till cosecutive 2 driving cycle.
Item | Detecting Condition | Possible cause | |
DTC Strategy | ● Determines if a high idle condition exists. | ● Poor connection ● Intake system/Vapor hoses for air leakage or disconnection ● Faulty Accelerator cable ● Faulty ETS motor ● Faulty TPS ● Faulty ETS system ● Faulty PCM | |
Enable Conditions | ● Normal Idle conditions ● Canister Purge Fuel Flow ≤ 100 ● Barometric Pressure 〉 72kPa ● Engine running ≥ 2 sec ● Air Intake Temperature ≥ -20℃ (-4℉) ● Coolant Temperature ≥ 0℃ (32℉) ● 11V ≤ Ignition Voltage ≤ 16V ● Above conditions met period 〉3 sec | ||
Thresh old value | ● Real engine speed - Target engine speed 〉200rpm | ||
Diagnosis Time | ● Continuous | ||
MIL On Condition | ● 2 driving cycles | ||
Ignition "OFF"
Connect Scantool and Engine "ON"
Monitor items which affect idle rpm on scantool.
Are those items on scantool displayed correctly ?
▶ Go to "Terminal and Connector Inspection" procedure.
▶ Check DTCs related to Mass airflow sensor(MAF),Injectors,Throttle position sensor(TPS), Purge control solenoid valve(PCSV), Acceleration position sensor(APS), Heated oxygen sensors(HO2S), ETS system
▶ Perform all repairs associated with those codes and go to "Verification of Vehicle Repair" procedure.
Many malfunctions in the electrical system are caused by poor harness 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 " System Inspection " procedure
Check intake/exhaust system for blockage
Visually/physically inspect the following items:
- Intake system for air leakage
- Vapor hoses for cracks or disconnection
Has a problem been found in any of the above areas?
▶ Replace or repair as necessary and go to "Verification of Vehicle Repair" procedure
▶ Go to "Visually check ETS System" as below
Visually check ETS System
Ignition "OFF"
Remove the air hose between MAF sensor and Throttle body.
Visually check the overall ETS system(Throttle valve,ETS motor,APS and TPS).
Has a problem been found?
▶ Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.
▶ Go to " Component Inspection" procedure.
Check Accelerator Cable
Ignition "OFF" ＆ Engine "OFF"
Check free play of accelerator Cable
Specification 1.0 ~ 3.0mm(0.04 ~ 0.12 in)
Is the measured resistance within specifications?
▶ Go to "Check TPS" as below
▶ Substitute with a known-good ETS motor and check for proper operation. If the problem is corrected, replace ETS motor and then do "ETS Initialization" and go to "Verification of Vehicle Repair" procedure.
Check ETS motor
Ignition "OFF"
Disconnect ETS motor connector
Measure resistance between terminals "1" and "2" of the ETS motor connector.
Specification: Approx. 1.275 ~ 1.725Ω at 20℃(68 °F)
Item | Sensor Resistance |
Coll Resistance (Ω) | 1.275 ~ 1.725Ω (20℃) |
Are the TPS resistance within specifications?
▶ Go to "Check TPS" as below
▶ Substitute with a known-good ETS motor and check for proper operation. If the problem is corrected, replace ETS motor and then do "ETS Initialization" and go to "Verification of Vehicle Repair" procedure.
Check TPS
Disconnect TPS connector and measure resistance between terminals 4 and 8 of the TPS connector.
Specification : Approx. 4.0~6.0kΩ( with throttle valve fully closed) at 20°C(68°F)
Disconnect TPS connector and measure resistance between terminals 1 and 5 of the TPS connector.
Item | Sensor Resistance |
TPS 1 | 4.0 ~ 6.0 ㏀ (20℃) |
TPS 2 | 2.72 ~ 4.08 ㏀ (20℃) |
Are the TPS resistance within specifications?
▶ Substitute with a known-good PCM and check for proper operation. If the problem is corrected,replace PCM and then go to "Verification of Vehicle Repair" procedure. If PCM needs to be replaced, do "ETS Initialization" after it is replaced.
▶ Substitute with a known-good TPS and check for proper operation.If the problem is corrected, replace TPS and then do "ETS Initialization". And go to "Verification of Vehicle Repair" procedure.
※ Procedure of ETS Initialization
1. Erase the trouble codes on PCM
2. Turn the ignition key off and keep this condition until the main relay is turned off.(It will takes 10 second)
3. Turn ignition key on more than 1second to record the throttle motor position on the EEPROM
After a repair, it is essential to verify that the fault has been corrected.
Monitor and record the Freeze Frame Data for the Diagnostic Trouble Code(DTC) which has been diagnosed.
Using a Scantool, Clear the DTCs
Operate the vehicle within conditions noted in the freeze frame data or enable conditions
Monitor that all rediness test have been verified as " Complete "
Are any DTCs present ?
▶ Go to the applicable troubleshoooting procedure.
▶ System is performing to specification at this time.
