DTC P0125: Engine Coolant Temperature Excessive Time To Reach Closed Loop: Description

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

The Engine Coolant Temperature (ECT) sensor monitors the temperature of the coolant. This input is used by the Powertrain Control Module (PCM) for engine control and as an enabling criterion for some diagnostics. The air flow coming into the engine is accumulated and used to determine if the engine has been driven within conditions that would allow the engine coolant to heat up normally to the thermostat regulating temperature. If the ECT does not increase normally or does not reach regulating temperature of the thermostat, diagnostics that use the ECT as an enabling criterion may not run when expected. This DTC will only run once per ignition cycle within the enabling conditions. This DTC will set when excess time is necessary in order to reach a minimum coolant temperature required for Closed Loop fuel control.