[Vwdiesel] Coolant Thermostat Valve

[Dave Cook]

The Unintended Consequences thread reminded me-my check engine light came on today for the first time since buying the car.  


Here is the code I pulled:

16512 - Coolant Thermostat Valve (N214) 
            P0128 - 35-10 - Temperature below Control Range - Intermittent

I have thought that maybe my thermostat may not be closing like it should based on length of time to warm up the engine, and how much the temp will drop immediately after starting (frost heater plugged in) indicating maybe a slug of cold coolant from the radiator is flowing into the motor.

So is is possible my thermostat is stuck open and this is telling the computer wonky info, thereby tripping the code?

Or am I way off track?

Thanks,

Dave Cook