Circuit Description

WARNING: This page is about a different car, the 2002 Isuzu Rodeo Sport and 2002 Isuzu Rodeo. However, it is still accessible from the selected car via links, so may be relevant.

PCM controls idle speed by adjusting an Idle Air Control (IAC) motor pintle. IAC is a bi-directional stepper motor driven by two coils. PCM applies current to IAC in steps (counts) to extend IAC pintle, increasing air flow. This method allows for highly accurate control of idle speed, and quick responses to changes in engine load. When PCM detects too low of an idle speed and is unable to adjust idle speed, DTC P0506 will set.

When DTC sets, PCM illuminates MIL on second trip after fault was detected. Vehicle operates in base shift logic on RPM only. PCM will store conditions present when DTC was set as freeze frame data in the FAILURE RECORDS data.

PCM will turn MIL off on third consecutive trip cycle during which diagnostic runs and fault is no longer recognized. A history DTC will clear after 40 consecutive trip cycles during which diagnostic runs and fault is no longer recognized. DTC can be cleared with scan tool, or by disconnecting battery voltage feed to PCM.