Engine Hot/AC Turned Off message

[iLikeEggs]

I was driving along on our first cold snap, 21 degrees out. I have the Cold Case aluminum radiator in so it takes longer to get up to operating temp and always runs a bit cooler on the guage. So then I get this message in the DIC. Interesting. Then the both fans start screaming and won't shut off. Then the temp guage goes dead. I get home and check a couple of videos and one recommends replacing the wiring pigtail for the CTS. Makes sense since I have 200k on it. So I pick up a new CTS and pigtail and put it on while it's raining out. Nothing changes. I do some more research and one guy says to pull the 10 Amp fuse in number 12 position, the ECM fuse. Wait 10 seconds and put it back in. What do you know? It worked.
Just put about 100 miles on it since then and normal operation.

 

[RooTBeeRthe1st]

Sounds to me like whoever installed the cold case didn't put a restrictor in the line to the expansion tank.

 

[iLikeEggs]

I have a restrictor (45acp shell casing). I took it out to diagnose another problem which turned out to be a small crack in the overflow tank and also a bad heater hose. Eventually I'll get around to putting it back in.

 

[iLikeEggs]

Update.... Still running strong with no problems. That fuse pull did the trick and only had to be done the one time.