I have a 06 2.2 93,000 miles I get a code 128 off and on, might go a month and no code then again might get that code twice a week. I replaced the coolant sensor still comes on. It seems to do it when the outside temp is around 40 to 50. Last summer with the ac on it never came on, started when the temp started to change. Runs fine, good heat, ac works fine, coolant runs about 182 to 192, any ideas??? Thanks

 

There may be more than 2 sensors.

 

Are you refering to the P0128 code? Engine Coolant Temperature (ECT) Below Thermostat Regulating Temperature.

Your t-stat is not closing completely and preventing the coolant from heating up to the required temp in the required time. Replace the t-stat and all will be good. The sensors are not the problem.

It's an easy job but if I recall it's about $300 + at the dealer. The t-stat should be about $30 or so.

 

Here is a link for you https://www.chevyhhr.net/forums/problems-service-repairs-42/temp-sensor-problems-31928/

In that thread there is a link to the how to thread for replacing the t-stat.

 

Well, there you go. lol

 

Thanks I'll give it a try

 

Replaced the stadt and that seems to be the problem Thanks