Thermostat Heater Control Circuit High

[bbradysaldana]

Hello!

My check engine light came on a few days ago, scanned it and the code came up as P0599- Thermostat Heater Control Circuit High.

Basically I would love to know these things:
1-If my car is safe to drive next week? I have a long commute to and from work.
2-Am I looking at a costly repair that is really invasive?
3-Can I do it myself? Mind you I am not completely in the dark about cars but I am by no means a "Knowledgeable" car person
and
4-what the hell is wrong with it anyways. Coolant issue? Actual thermometer?

Also, I live in Las Vegas, NV and it is SUPER HOT out here. Could this be something that is caused by the extreme heat?

I have read a few articles but they all say something different.
Thank you for your answers in advance!!!
Britt

 

[Maddmatts]

The code implies that there's an open or shorted circuit with the electronic thermostat's heating element.

Old thermostats use a wax pellet that expands when heated. The expansion is used to open a valve that lets the hot coolant flow into the radiator.

Modern cars use a thermostat using the same concept but adds an internal heating element to allow the engine computer to more directly control when it should open to get the engine up to operating temp quicker.

I'm not sure at what temp the thermostat opens by itself but there might be a risk of engine overheat in your situation as I think they naturally open hotter.

It's possible the connector to it has come loose and just needs to be plugged back in or reseated. Cost and replacement is dependant which engine you have. The 1.4T's thermostat is noticeably cheaper than the 1.8's based on RockAuto.

 

[bbradysaldana]

Thank you! Ill have to look and see. Do you think that the car is safe to drive as long as a make sure not to over heat??

The code implies that there's an open or shorted circuit with the electronic thermostat's heating element.

Old thermostats use a wax pellet that expands when heated. The expansion is used to open a valve that lets the hot coolant flow into the radiator.

Modern cars use a thermostat using the same concept but adds an internal heating element to allow the engine computer to more directly control when it should open to get the engine up to operating temp quicker.

I'm not sure at what temp the thermostat opens by itself but there might be a risk of engine overheat in your situation as I think they naturally open hotter.

It's possible the connector to it has come loose and just needs to be plugged back in or reseated. Cost and replacement is dependant which engine you have. The 1.4T's thermostat is noticeably cheaper than the 1.8's based on RockAuto.

 

[Maddmatts]

I think it'll be safe to drive for 5 or so minutes at a time with a few hours between each drive to let it cool down. I don't really know beyond that.

There is a light on the cluster that comes on specifically to warn about overheating and the manual has a section (pg.10-19 for 2012's) on what to do if that light comes on.

 

[ib2loud]

I had this code and the thermostat was stuck open I guess. It never overheated but as soon as I replaced the thermostat assembly it was good to go.

It's a fairly easy fix if you can handle a little coolant on your hands. I think the cost was around $80.