The Idle Speed Control Actuator(ISCA) is installed on the intake manifold and controls the intake airflow that is bypassed around the throttle plate to keep constant engine speed when the throttle valve is closed. The function of the ISCA valve is to maintain idle speed according to various engine loads and conditions, and also to provide additional air during starting. The ISCA valve consists of an opening coil, a closing coil, and a permanent magnet. Based on information from various sensors, the PCM controls both coils by grounding their control circuits. According to the control signals from the PCM, the valve rotor rotates to control the by pass airflow into the engine.
PCM sets DTC P1507 if the PCM detects that the ISCAV(CLOSE) control line is open or short to ground.
Item
Detecting Condition
Possible Cause
DTC Strategy
Electrical check
Open or short to ground in harness
Poor connection or damaged harness
Faulty ISCA valve
Enable Conditions
6V < Battery voltage < 16V
18~23% > PWM output > 77~82%
Threshold Value
Open circuit or short circuit to ground
Diagnostic Time
1 sec.
MIL On Condition
2 Driving Cycles
Temperature
Opening Coil(O)
Closing Coil(O)
20?(68?)
11.1~12.7
14.6~16.2
? ISCA Control Circuit Waveform during IG ON
? ISCA Control Circuit Waveform during Idle