my light has been on for about 2 weeks now and i can't figure out why,
code from autozone states, cooling system performance, low coolant level probable cause (coolant isen't low) failed radiator or water pump (it's not overheating and has been at the same temp for years) and lastly check ECT sensor and i changed that last week (coolant temp sensor)
anybody have any advice on this?
You said you've replaced the coolant tempature sensor so that's rulled out.
Are both the fans working?
- Turn the car on
- Put the fan on and push the a/c button.
- Are both fans working? If not, there's your problem.
Quick easy way to check water pump and thermostat:
- Put the fan on with temperature set to hot.
- Does heat come out readily from the vents?
If not, Probably the water pump is gone. If it does, likely the thermostat is gone
water pump and thermostat should have been done. either can cause that code. honestly the water pump should have been replaced with the t-belt. especially since they are plastic and are known to crack/fall apart... t-stat should be done just because its pretty much tired out by 100k. mine went out at 110000. i know t-belt replacement is expensive but its cheaper than buying a new engine or a new car...and if you know your way around a car you can do it yourself
edit: here is the link for the thermostat replacement
Last edited by Jetta02AWP; 05-12-2012 at 10:08 PM.
the car doesn't have to overheat necessarily in order for the pump to be suspect. the engine may get hotter than normal under load, and it can overheat. remember there may be some propellers left on there that haven't broken off. it will fail on you if it was not replaced. its just a matter of time. i'm not trying to scare you and i hope i don't come off like that. just trying to be as factual and informative as i can.
The spider cracks around the shaft were allowing it to spin under little pressure but as soon as I put the car under a load the impeller would stop spinning and the car would overheat
But again, this was after I had already replaced the thermostat, water pump, and looked into any other culprit, so if you don't have an aftermarket exhaust, or done a cat-delete or something...then I would replace all parts you need to anyways, because you eventually will have to, and you might as well before something actually goes out
edit: you will most likely know if it is your water pump
^ this is very true. i have seen this before as well as chunks missing and the whole impeller missing. OP just replace it and save yourself the trouble. or do the t-stat first and check the water pump as previously suggested. but honestly it will most likely fail before the next t-belt is due.
Bumping this thread for an answer, got the p2181 today. Temp is normal, both fans run, heat comes out when I turn heat on. Pump was replaced 10k ago (at 80k) with metal impeller. So its the t-stat or the ECT?
I will search how to do the ECT, just wanted to know if it could be anything else.
I had this issue today also. I had it happen a year or so ago and was told it was the coolant temp sensor. Had it replaced, light came back on the next day, had it replaced again under warranty, light came on again a few days later. Brought it to a guy I trusted more and had it replaced and it has been off for a year. Came on today on my way home from work after just giving the engine some gas. Got the code cleared from the auto parts store and didn't come back on after driving around. I will have to get the water pump and timing belt soon so maybe that was my issue this time? Stupid generic CEL codes....
So apparently I've been driving around for a month now with this CEL. I stopped at an acquaintance's house today who has a vagcom, returned p2181, coolant system. So same thing as a generic scanner.
I guess I'll order an ECT sensor, though it reads normal all the time. My current one IS a green top also.
Guys, I get the same code on my '04 1.8 Jetta.
Replaced the CTS
Car does NOT overheat.
At operating temperature, I turn on the A/C and my fans don't immediately turn on.
HOWEVER, they do turn on and cycle for about 10-15 seconds at a time then turn back off again.
I have been getting p2181 for months on my jetta changed water pump thermostat and temp sensor. The more research ive done I have found lots of other people with the same issue. I have read a bad coolant mix will cause this also. Mine only gives me problems in the colder months after that it goes away for the summer. I just clear the code and keep driving mine since draining the coolant system and refilling with g12 costs too much imo to fix this little cel.