5.
Read "DTC Status" parameter.
The ISCA (Idle Speed Control Actuator) is designed to maintain a steady desired idle speed. Idle airflow is adjustedthrough the idle air actuator 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.
If there is Open or Short to ground in ISCA(closing coil) circuit, PCM sets DTC P1507.
Item | Detecting Condition | Possible Cause |
DTC Strategy | ● Circuit continuity check, low (Closing coil) | ● Poor connection ● Open or short to ground in control circuit ● ISCA |
Enable Conditions | ● Vehicle speed = 0 ● Coolant temperature ＞ 70℃ ● Intake air temperature ＞ -6℃ ● Altitude ＜ 3000m ● Idle status ● Monitoring of VSS is ended ● No error on the related sensors. (VSS,ECTS,IATS,etc) | |
Threshold Value | ● Shorted to ground or disconnected | |
Diagnostic Time | ● Continuous | |
MIL ON Condition | ● 2 driving cycle |
Temperature [℃ (℉)] | Closing Coil Resistance (Ω) | Opening Coil Resistance (Ω) |
20 (68) | 14.6 ~ 16.2 | 11.1 ~ 12.7 |
Connect scantool to Data Link Connector(DLC).
IG "ON".
Select "Diagnostic Trouble Codes(DTCs)" mode, and then Press F4(DTAL) to check DTC'sinformation from the DTCs menu
Confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditionsnoted in the freeze frame data or enable conditions noted in the DTC detecting condition.
Read "DTC Status" parameter.
Is parameter displayed "History(Not Present) fault"?
History 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 wasrepaired 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 "Terminal ＆ Connector Inspection" 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 "Power circuit inspection" procedure.
Key "OFF".
Disconnect ISCA connector.
Key "ON".
Measure the voltage between terminal 2 of ISCA harness connector and chassis ground.
Specification : B+
Is the measured voltage within specification?
▶ Go to "Control circuit inspection" procedure.
▶ Repair Open or Short in power circuit and then, go to "Verification of Vehicle Repair" procedure.
Check Open in control circuit.
Key "OFF".
Disconnect ISCA connector and ECM connector.
Measure the resistance between terminal 3 of ISCA harness connector andterminal 22/CGGA-A of PCM harness connector. [A/T]
Measure the resistance between terminal 3 of ISCA harness connector andterminal 25/CGGM-K of ECM harness connector. [M/T]
Specification : Below Approx 1Ω
Is the measured resistance within specification?
▶ Go to "Check Short in Control circuit" procedure.
▶ Repair Open in control circuit and then, go to "Verification of Vehicle Repair" procedure.
Check Short in control circuit.
Key "OFF".
Disconnect ISCA connector and ECM connector.
Measure the resistance between terminal 3 of ISCA harness connector and chassis ground.
Specification : Infinite
Is the measured resistance within specification?
▶ Go to "Component inspection" procedure.
▶ Repair Short to ground in control circuit and then, go to "Verification of Vehicle Repair" procedure.
ISCA visual check.
Key "OFF".
Disassemble ISCA.
Check contamination, damage or stuck on ISCA.
Check the operating sound when key turns "OFF" to "ON".
Is ISCA O.K?
▶ Go to "ISCA check" procedure.
▶ Substitute with a known - good ISCA and check for proper operation.
▶ If the problem is corrected, replace ISCA and go to "Verification of Vehicle Repair" procedure.
ISCA check.
Key "OFF".
Disassemble ISCA.
Measure the resistance between terminal 1 and 2 of ISCA harness connector. (Component side)
Measure the resistance between terminal 2 and 3 of ISCA harness connector. (Component side)
Temperature [℃ (℉)] | Closing Coil Resistance (Ω) | Opening Coil Resistance (Ω) |
20 (68) | 14.6 ~ 16.2 | 11.1 ~ 12.7 |
Is the measured resistance within specifications?
▶ 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. So, check poor connections and the related circuit between ECM and component thoroughly. Repair as necessary and go to "Verification of Vehicle Repair" procedure.
▶ Substitute with a known - good ISCA and check for proper operation.
▶ If the problem is corrected, replace ISCA and go to "Verification of Vehicle Repair" procedure.
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.
