Circuit Description
WARNING: This page is about a different car, the 2002 Oldsmobile Intrigue, 2001 Oldsmobile Intrigue, and 2000 Oldsmobile Intrigue. However, it is still accessible from the selected car via links, so may be relevant.
The PCM uses the ECT sensor to monitor the engine for an over temperature condition. This condition occurs when the coolant temperature is above 131°C (268°F). When an over temperature condition is present, DTC P1258 will set. The PCM will disable two groups of four cylinders by turning OFF the fuel injectors. By switching between the two groups of cylinders, the PCM is able to reduce the temperature of the coolant.