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 Actuator Closing Coil Signal Low

DESCRIPTION
The Idle Speed Control (ISC) actuator has two coils that are driven by separate ECM driver stages. Depending on the pulse duty factor, the equilibrium of the magnetic forces of the two coils will result in different directions for the magnetic forces of the two coils which will result in different p0sitions for the actuator. In parallel to the throttle valve, a bypass hose line is arranged where the SC actuator is inserted.

FAILURE CONDITIONS
The ECM will set a code and the MIL will turn on if ISC actuator's opening coil driver stage [for P1505, P1506] or closing coil driver stage [for P1507, P1508] is shorted to battery voltage during two driving cycles.

Circuit Diagram:

Test Procedure: