[DUK]

My wifes car is at it again. Seems every time the ambient temperature gets below freezing the coolant sensor quits working. This is the third new delco sensor and did it once last year and now twice this year.

I can get the sensor and gauge to work if I reset the ecm (by unhooking the ground or using the obd2 tool). So I think I have eliminated the thermostat being the culprit.

Anyone else have this?

Oh and being this is my first post.... HELLO EVERYONE

 

[Starship]

Welcome to the forum. If you're reading DTC P0128, see TSB 07-06-02-003 at http://ww2.justanswer.com/uploads/heavychevy396/2010-01-23_123909_2006_Chevrolet_Uplander_P0128.pdf. Otherwise, you may want to describe your problem in greater detail (what does "quits working" mean?).

 

[DUK]

Thanx Starship. That looks to be the culprit.

My idea of quits working is it quits working. Goes from showing a normal temp and then to 0 (or C on our gauge).

 

[Starship]

I'm not sure in that case. It goes to C on the instrument cluster but what does the OBD scanner say? On the ECTS circuit, high resistance means low temperature and vice versa. If it read something ridiculous like -40 degrees F suddenly, there probably is a circuit problem (open or poor connection).

 

[DUK]

OK I'll have to take a look at it.

With the snow it may take me a day or two.

 

[DUK]

Ended up being a thermostat. The rubber seal on the plunger (never saw a seal here before) folded over and wasn't letting it close. Must have been doing it sometimes, then not, as the problem seemed to be intermittent.

Took 45 minutes to change. Take the air tube off, drain the radiator, take the upper radiator hose off, take the lower hose off, fight the little bracket holding an electrical connector off the stud on the thermostat housing (this was the toughest part), remove the thermostat housing, remove and replace the thermostat, and reverse the procedure.

Dealership said 4 hours to do it.

 

[Starship]

Thanks for the update. I wouldn't have suspected a flaky thermostat, no way. Congrats on getting to the bottom of it. Just in time too, I think we're in for a real cold winter.

 

[DUK]

You can say that again.