P0125 Fix Insufficient Coolant Temperature For Closed Loop Fuel Control
You need to determine whether the engine coolant temperature sensor is telling the truth and the engine really isn’t coming up to operating temperature, or whether the sensor is bad. Many DIYers rush to replace the sensor. And yes, they do go bad. But not nearly as often as the thermostat.
So start your diagnostics by checking coolant level. If it’s low, fill it. Then, using an infra-red thermometer, check the temp around the thermostat housing. At operating temperature, it should be about 195°. If it doesn’t reach that point, you’ve got a thermostat that’s stuck open. A thermostat and gasket is cheaper than a temp sensor.
© 2012 Rick MuscoplatPosted on by Rick Muscoplat