Circuit Description

WARNING: This page is about a different car, the 2004 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.

The engine control module (ECM) monitors the temperature of the engine coolant for engine control and as an enabling criteria for some diagnostics. The amount of air flow into an engine is proportional to the amount of heat an engine generates. The ECM monitors the amount of air flow into the engine to calculate engine coolant temperature (ECT). The ECM uses the calculated temperature to determine if the engine has warmed up to the closed loop temperature. If the coolant temperature does not increase normally or does not reach the closed loop temperature, diagnostics that use the ECT as enabling criteria, may not run when expected. If the ECT fails to reach the closed loop temperature, before a predetermined amount of air flow enters the engine, this DTC sets.