Kadorja

I posted this in tech but maybe you guys have some insight as well.

So while driving to work today my coolant temp dropped all the way down and on the DIC it would just say "XXX" as the temp. Everything else was reporting normally. The car ran fine but did turn off the A/C as a precaution. Air coming out of the vents was ice cold and a check under the hood showed no signs of overheating.

Any ideas where the sensor and wiring is?? Hopefully the sensor just went out or the wiring possibly broken/melted.

Streetk14

Sensor is screwed into the driver side cylinder head right in front of the #1 spark plug. I've never been boneheaded enough to do it, but I've heard of a bunch of people damaging the sensor when changing spark plugs. You could also have air in the cooling system.

Kadorja

So I hooked up the code reader and while I had 17 old codes (from the rebuild) I had 0 active codes. I cleared the codes and as soon as I did the coolant gauge started working and the DIC worked as well.

Someone also suggested air in the system so I may run it with the cap off to try to purge it but the shop actually had a system that forced the fluid in and old air out. Rather be safe than sorry. Also might throw in additive to help her run cooler. I wanted to scrub the crap off the rad but the brush was too large.

HoustonSVT

Good Luck in finding what the problem is, I have been dealing with it for several months now. I just keep resetting the code. In searching here on the forum, I have read that it could be: burnt wires, temp sending unit on driver head, problem in the tune with the fan setting's and so on.
I tried replacing the temp sending unit, but that didn't fix it. I am sure it is something in tune because it happened to me only after having my car worked on then tuned for it. One or two shops I spoke to said there is something in the tune that will cause this.

Blackonblacksls

I had a problem like this with my 2011 camaro and I replaced the coolant sensor and it stopped causing issues.

old motorhead

A different 160* thermostat fixed a similar issue on my '08 coupe. On mine, the MR Gasket t'stat would open too soon and too wide. The PCM would think there was something wrong with the temp sensor when it cooled down that much and that quick. Then, that same DIC message would appear. I jerked the Mr Gasket t'stat out and installed a Lingenfelter 160 'stat and never had that trouble again.

Josh@AandASuperchargers

I will attach a screen shot of what you need to change in the tune to fix this, it's not a mechanical issues. It's the PCM that is not happy.

DTC P0128 needs to be unchecked and set to No Error Reported.