Check Engine Light Due to Ignition Component/Engine Coolant Temperature Sensor Failure on Volkswagen Jetta

Problem Description and Possible Solution

Due to an ignition component and/or engine coolant temperature sensor failure, the Check Engine Light may illuminate. Replacement of the failed component will be necessary to correct this concern.

Problem Data
RepairPal Verified
Average mileage: 95,582 (35,000–200,000)
6 model years affected: 2000, 2001, 2002, 2003, more2004, 2005
41 people reported this problem
Viewing 1 - 14 of 14 comments
check engine light has come on the code read p2181 which is cooling system malfunction. I have changed the ect sensor but still have the engine light on.
Had the water pump and timing belt replaced and have been back numerous times because check engine light keep coming on. Have changed the temperature sensor and still come on..
Coolant System malfunction. It was only the water temperature sender. It is a $15 part and a 10 minute fix if you want to do it yourself. It is very easy. You will probably pay a couple hundred bucks if you take it to the shop.
my car would not pass smog, the check engine light goes off and on, now my car will not start.
Service engine soon light was lit, dealer determined the problem and replaced the temperature sender.
CEL - changed the temp sender, but still have the problem
my car would have very rough start ups and at first i figured it was bad spark plugs until i researched it and found out it was a faulty coolant temp. sensor, after replacing the car no longer has rough start ups and i maintain regular 3 month maintanance
My temp gauge goes up to 190 then drops back down on it's own.
When I first start my car it runs rough with no power,the engine light blinks then after a couple minutes of driving it the car runs perfect and the engine light stops blinking but stays on
engine lite on dashboard (yellow) on as of august 2015, diagnosed by mechanic as coolant-sensor "troublemaker". repair has to wait,can not afford an other expense .Electrical problems are part of this product, as headlite,taillite,back-up,stoplites need repairs (replacements) on a by annual interval !
Leak found in coolant temp
Ignition light stays on n
Replaced fan, thermostat, and coolant.
I repaired at dealership