P0125

CIRCUIT DESCRIPTION
An 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 criteria 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 coolant temperature does not increase normally or does not reach regulating temperature of the thermostat, diagnostics that use engine coolant temperature as enabling criteria, may not run when expected.

This DTC will only run once per ignition cycle within the enabling conditions.

This DTC will set when there has been excessive time to reach a minimum coolant temperature required for closed loop fuel control.

CONDITIONS FOR RUNNING THE DTC
^ DTCs P0110, P0111, P0112, P0113, P0117, P0118, P0128, P1114, P1115 are not set.
^ Minimum air temperature is more than -7°C (19°F).
^ Start up engine coolant temperature is below 40°C (104°F) with manual transmission vehicles.
^ Start up engine coolant temperature is below 20°C (68°F) with automatic transmission vehicles.
^ Region 1
Air temperature above 10°C (50°F) and the start up coolant temperature is above 10°C (50°F).
^ Region 2
Air temperature above -7°C (19°F) and the start up coolant temperature is between -7°C (19°F) and 10°C (50°F).
^ Region 3
Air temperature above -7°C (19°F) and the start up coolant temperature is between -40°C (-40°F) and -7°C (19°F).

CONDITIONS FOR SETTING THE DTC
^ Region 1 (Automatic transmission)
Engine run time is over 139 seconds to achieve closed loop temperature of 20°C (68°F). The calibrated minimum amount of air flow has been exceeded. The maximum idle time has been less than 104 seconds.
^ Region 1 (Manual transmission)
Engine run time is over 325 seconds to achieve closed loop temperature of 40°C (104°F). The calibrated minimum amount of air flow has been exceeded. The maximum idle time has been less than 250 seconds.
^ Region 2 (Automatic transmission)
Engine run time is over 251 seconds to achieve closed loop temperature of 20°C (68°F). The calibrated minimum amount of air flow has been exceeded. The maximum idle time has been less than 188 seconds.
^ Region 2 (Manual transmission)
Engine run time is over 400 seconds to achieve closed loop temperature of 40°C (104°F). The calibrated minimum amount of air flow has been exceeded. The maximum idle time has been less than 300 seconds.
^ Region 3 (Automatic transmission)
Engine run time is over 324 seconds to achieve closed loop temperature of 20°C (68°F). The calibrated minimum amount of air flow has been exceeded. The maximum idle time has been less than 243 seconds.
^ Region 3 (Manual transmission)
Engine run time is over 475 seconds to achieve closed loop temperature of 40°C (104°F). The calibrated minimum amount of air flow has been exceeded. The maximum idle time has been less than 375 seconds.

DIAGNOSTIC AIDS
DTC P0125 is designed to detect a skewed ECT sensor.

If a P0125 and a P0128 are set a faulty thermostat may be the cause (manual transmission).

TEST DESCRIPTION

Steps 1-9:

Steps 10-11:

The numbers below refer to the step numbers on the diagnostic table.
3. This step tests for excessive resistance in the ECT circuit.
7. This step tests for a skewed sensor through the range of temperatures affecting this DTC.