Hi all Benz members, this morning, my check engine light came on.
After using friend's OBD tool, the faulty code is P0128, thermostat issue.

But my car still reach warm engine temperature like usual, no delay and no engine over heat. Also I have warm hot heater air from air conditioning.

Is this still sign of bad thermostat?

My car is 2009 C230 V6 4Matic in Toronto.

Thank you for your input.

 

I would say so. This thermostat is well over engineer! It got a center shaft which is heated to help opening of one of the three stages valves! I don't see anything else that can trigger this message…. I just replace mine, took me about two hours. And the thermostat was order from states for $112.00 + shipping and duties… Just in case , take a good look at the wires connected to it and if you got access to an ohmmeter, there should be 15.2 ohms between the two connections...

 

This is a fault with thermostat, this will require replacement, electronic thermostat.

 

Thanks guys for your advice and help, much appreciated.

I drove few days with CEL light on, to monitor my engine temp and heater temp, it looks very normal. So I used another OBD tool (better model), to clear the CEL. So far it has been 2 days, the CEL remains off and no faulty P0128 code.