Questions & Answers for: Mercury code p0128

2005 Mercury Monterey with check engine code P0128; what does this mean? it is an error showing some issue with thermostat. it means the engine isnt getting warm enough, replace the thermostat.

...code P0128; what does it mean? P0128 is Coolant Thermostat ( Coolant Temp Below Thermostat Regulating Temperature ). The thermostat may be stuck open, preventing normal operating Temperature from ...

2004 mercury mountaineer check engine code P0128 check engine light came on and had it tested and came up with code P0128. what is this and how can it be fixed should have told you when checked?

...code comes back, the problem is likely going to be the result of the above causes (faulty thermostat, faulty ECT sensor, or a low coolant level). Other ECT sensor and circuit related DTCs: P0115, ...