P0125
DTC P0125
CIRCUIT DESCRIPTION
An engine coolant temperature (ECT) sensor monitors the temperature of the coolant. This input is used by the engine control module (ECM) 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.
If the ECM detects the calibrated amount of air flow and engine run time have been met, and the engine coolant has not met the Closed Loop temperature, DTC P0125 sets.
DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P0125 Engine Coolant Temperature (ECT) Insufficient for Closed Loop Fuel Control
CONDITIONS FOR RUNNING THE DTC
- The engine is running.
- The start-up engine ECT is less than 14°C (57°F).
- DTC P0125 will run once within the enabling conditions.
CONDITIONS FOR SETTING THE DTC
- The calibrated amount of air flow has been met.
- The calibrated amount of engine run time has been met.
- The minimum ECT for Closed Loop of 37°C (99°F) has not been met.
ACTION TAKEN WHEN THE DTC SETS
- The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
CONDITIONS FOR CLEARING THE MIL/DTC
- The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
- Clear the MIL and the DTC with a scan tool.
TEST
