|P0125 – Insufficient Coolant Temperature For Closed Loop Fuel Control|
|Description: Indicates the engine coolant temperature (ECT) or the cylinder head temperature (CHT) sensor has not achieved the required temperature level to enter closed loop operating conditions within a specified amount of time after starting the engine.
Possible Causes: • Insufficient warm up time
• Low engine coolant level
• Leaking or stuck open thermostat
• Damaged ECT sensor
• Damaged CHT sensor
Diagnostic Aids: Compare the thermostat specification to the actual ECT using the engine temperature PID (ECT or CHT). The temperature reading should be similar when the engine is at a normal operating temperature.