DTC P0125: Engine Coolant Temperature Insufficient For Closed Loop Fuel Control: Description

Engine Coolant Temperature (ECT) sensor monitors temperature of the coolant. This input is used by the Powertrain Control Module (PCM) for engine control and as an enabling criteria for some diagnostics.

The air flow into the engine is accumulated and used to determine if the vehicle has been driven within the conditions that would allow the engine coolant to heat up normally to the Closed Loop temperature. If the coolant temperature does not increase normally or does not reach the Closed Loop temperature, the diagnostics that use engine coolant temperature as enabling criteria may not run when expected. This DTC will only run once per ignition cycle within enabling conditions.

If the PCM detects the calibrated amount of air flow and engine run time has been met and the engine coolant has not met the Closed Loop temperature, DTC P0125 sets.