P1508

****Some values in these diagnostic procedures are incorrect, refer to the following 2 tables for updated values or to TSB - 03-36-024 for updated values****










DTC P1508 Idle Speed Control Actuator Signal High of Coil *2

DESCRIPTION




The Idle Speed Control Actuator (ISCA) is installed on the throttle body and controls the intake airflow that is bypassed around the throttle plate. The function of the ISCA is to maintain idle speed according to various engine loads and conditions, and also to provide additional air during starting. Moreover, it performs electronic the dash pot during deceleration. The ISCA consists of an opening coil, a closing coil, and a permanent magnet. Based on information from various sensors, the ECM controls both coils by grounding their control circuits. According to the control signals from the ECM, the valve rotor rotates to control the bypass airflow into the engine.

DTC Detecting Condition:

Specifications:

Schematic Diagram:

Signal Waveform:

Step 1 - 2:

Step 3 - 4:

INSPECTION PROCEDURE