Radiator fan constantly run high. Switch on or off.

Question

'06 Mercedes C230 Sport V6 M272 engine.
Fan runs on high with the switch ON or OFF.
Throwing codes P0116, P0118 and P0128.
New fan. Bench tested fan relay. Sat.

Answer 1

P0116 Coolant temperature too high

P0118 Coolant temperature sensor has a short circuit to positive or open circuit

P0128 Coolant temperature rises too slowly

You have a code for the thermostat P0128 this code is more a mechanical for the thermostat, then there a code for the coolant temperature sensor, If the ECM does not see a coolant temperature signal the coolant fan will turn on.even with the car ignition switch off . You have a variety of code that may have been set due to disconnection of the there coolant temperature sensor, if not replace the coolant temperature sensor, Because there is a P0128 replace the thermostat also.