CEL - p0128 with stock thermostat

[mnunes]

So today I got a CEL on my way home from work. First thing I thought was to check oil pressure, temperature, etc. All look fine, but the temperature is a bit low.

Got home, pulled the code and it's P0128: coolant temperature below thermostat regulating temp (or something like that). Yeah, the temperature was a bit low, but this is the stock thermostat and it was about 65-70*F outside.

I did get the oil changed a few days ago (at the dealer). Could they have jarred a sensor loose somewhere that would cause something like this?

[giznome]

I've had that code twice now, but I switched to a 170 thermostat. Not sure why yours would be pulling that code. Mine has only done it when it's been cool ouutside, and I'm really babying it, so it takes a while to warm up. I don't think that's a loose sensor though in your case.

[chargershed]

So today I got a CEL on my way home from work. First thing I thought was to check oil pressure, temperature, etc. All look fine, but the temperature is a bit low.

Got home, pulled the code and it's P0128: coolant temperature below thermostat regulating temp (or something like that). Yeah, the temperature was a bit low, but this is the stock thermostat and it was about 65-70*F outside.

I did get the oil changed a few days ago (at the dealer). Could they have jarred a sensor loose somewhere that would cause something like this?

It's possible, it's also possible that your t-stat is stuck open which will throw that code also...

[mnunes]

It's possible, it's also possible that your t-stat is stuck open which will throw that code also...
So, if that's it, is there an easy way for me to take care of it, or should I drop by the dealer in the morning and have them do it (under warranty)?

[chargershed]

So, if that's it, is there an easy way for me to take care of it, or should I drop by the dealer in the morning and have them do it (under warranty)?

Well, as a Service writer for a DCx dealership, the politically correct thing for me to say would be to take it in under warranty...however, if you go to the lx forums and search for 180 degree t-stats... well, lets just say that you didn't hear that from me...yes there is an easy way to change your t-stat... the reason I think it is your t-stat is that the lx have a fail safe type that can only stick open... and that sounds like what you are describing... if you want to wait until this morning when I get to work, I'll check on TSB's for that same condition...

[mnunes]

Thanks, chargershed. I dropped it by the dealer this morning (service opens at 8am on Saturdays!). Service writer agreed that it sounded like a stuck thermostat (nothing obvious in the TSB list on 300cforums (http://www.300cforums.com/forums/tsb-recall-forum/15480-tsbs-complete-list-all-tsbs-recalls-issued-2005-2007-lx-models.html)).