need help with p2181

[devildog89]

So the code poped up, everything still seems to work properly. Heat is good, aircon is good, fans still blow. From what I have read its the thermostat but I would like some second opinions on this before I fix it for nothing. The only thing that comes up is that I think I may be down a little on power, mpg, and the thermostat on the dash never goes up but like I said, the car runs fine like nothing even happened?

What do you guys think? Any other sensors I should get aside the one in the thermostat group just to be safe?

[devildog89]

The code from the cel is p2181. Should have specified. My bad

[Goose The Moose]

Never had that problem so I can't speak from experience...
But all codes that you would ever hate to see on your Audi, and more, and possible solutions are all mapped out on the wiki.ross-tech.com
This site is always a good start.

http://wiki.ross-tech.com/wiki/index...3/P2181/008577

[SlickFix]

Have you cleared the code to see if it comes back? That's what I would do. I only worry about codes that keep coming back after I clear them.

[devildog89]

Yes, deleted the code, came back fast. So any idea on what sensors I may need to replace?

[diagnosticator]

There are two coolant temp sensors. One is behind the head in the coolant distribution flange fitting, and the other is in the lower rad hose. It's either of those sensors, or the t-stat.

Since you said the temp gauge is not coming up to normal indicated operating temp, either the sensor behind the head is bad, or the t-stat is malfunctioning. The temp sensor in the lower rad return hose does not control the temp gauge, but the ECU uses it to evaluate if the cooling system is working right, and or if the rad fan needs to run. Replace the sensor in the coolant flange first. If that doesn't fix the DTC, then the t-stat must be replaced.

[AutoMax]

There are two coolant temp sensors. One is behind the head in the coolant distribution flange fitting, and the other is in the lower rad hose. It's either of those sensors, or the t-stat.

Since you said the temp gauge is not coming up to normal indicated operating temp, either the sensor behind the head is bad, or the t-stat is malfunctioning. The temp sensor in the lower rad return hose does not control the temp gauge, but the ECU uses it to evaluate if the cooling system is working right, and or if the rad fan needs to run. Replace the sensor in the coolant flange first. If that doesn't fix the DTC, then the t-stat must be replaced.

This is 100%. If you haven't changed the sensors in a while may as well raplace both the one on the rad hose and back of the engine. I think they're like 20 each. If you have leaks around the rear sensor replace the wntire flange and save the future headache. If problem persists change thermostat housing / sensor.