Circuit Description

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

Misfire is monitored as a function of Combustion Quality (CQ) signals generated from ION Sensing Module system. Combustion signals represent degree of combustion in each cylinder. Misfire is detected when combustion signal is below a predetermined value. DTC P0300 will determine if a multiple cylinder misfire is occurring by monitoring CQ.

When DTC sets, PCM illuminates MIL on second trip after fault was detected. If misfire is severe enough to cause possible catalytic converter damage, PCM will flash the MIL as long as the misfire remains at catalyst damaging levels. PCM will disable Torque Converter Clutch (TCC). 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 P0300 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.