[RobDob]

Morning all

Out of the blue driving to work, my 2010 2500HD tells me 'ENGINE HOT, A/C TURNED OFF'. The water temp gauge is stuck at the lowest reading as if it's not working. I checked under the hood and the engine isn't any hotter than normal.

Driving home from work, same issue but then the engine warning light came on! I pulled over again, and all seems well under the hood, so I carried on home.

The coolant level was a little low, but nowhere near the lowest level so I topped it up. I then disconnected the battery for 10 mins and the problem seems to have gone away, although I haven't had time to drive it yet to see if the water temp gauge is back to normal.

I've had a look around the forum but can't find the exact same symptoms. Has anyone had this problem before?

Many thanks

Rob

 

[mjwhoopie]

Had the same message come up on my 08 2500HD 6.0 last night on the way to dinner. outside air temp was around 15 degrees. had the climate control set for defrost and lower heater port split, selected full hot.

Temp gauge went to "0", message on DIC engine hot turn off ac.

My first thought was that I had lost coolant. Nope. When I got off the street into a parking lot I checked under the hood. Coolant level was good upper radiator hose was not too hot to touch.

My thought is the temp sensor failed or I have a sensor wire broken.

I did a search on this forum. The people with the 4.3 seem to be having this issue a lot.

The current fix seems to be:

Replace the thermostat and temp sensor. A few have found the 'stat stuck open.

Seeing how it's not even up to 25 Degrees yet today, I'll get parts and do it tomorrow, it's supposed to get to 52.

Fingers crossed!

Mike

 

[mjwhoopie]

Quick update.

Changed the temp sensor, $30 @ Autozone, Cleaned the connector with some alcohol. Topped of the coolant, I lost about a 1/2 cup during the chg.

Just got back from an errand, 30 mile round trip, Ops good, no leaks, gauge is acting normally, no messages.

 

[RobDob]

Great, thanks.

I'll look into a new thermostat and temp sensor.

Don't have part numbers to hand by any chance do you?!

Many thanks

Rob

 

[mjwhoopie]

sorry I haven't responded sooner Rob. I've been working double shifts and Holiday stuff.

I used a "Duralast" PN SU112.

 

[mjwhoopie]

Well, I had the same message pop up last night. OAT's below 15 Degrees F. Coolant temp read normal at first. Then went to zero for my drive home from the store. Hard restart. Rpm went to 3000 and held for around 30-45 secs, then returned to normal.

Fired up the truck to come to work this morning, apx 6 degrees F, DIC message was on for 2-3 sec. Temp gauge operated normal on the way to work.

I'm ordering a new sensor, going AC DELCO this time.

Anyone else having issues here???

 

[RobDob]

My problem disappeared but has just occurred again! I'll definitely get round to replacing those parts this time!

Also, not sure if it's caused by the same issue, but my heater only blows hot air when the temp is set to max; just one notch down on the temp and it goes to cold air!

Would thermostat & temp sensor be causing that too?

Many thanks

Rob

 

[mjwhoopie]

I don't think that would be related. That sounds more like a mix door motor or control issue.

 

[2012SierraX83]

I recently had this problem, and was able to resolve it by replacing the thermostat with a Duralast 180 degree thermo instead of the stock 195 degree thermo.

 

[nestle239]

I had this problem coming home yesterday. I have the 4.3 silverado work truck, 2013 had it over 5 years and never changed the coolant. The ENGINE HOT, AC TURNED OFF came on. Engine seemed perfectly cool, probably "under-heated" if anything. Next morning I checked the coolant and it was slightly low. I added half a gallon on dex-cool premixed 50/50. Drove it 25 miles on the highway, same issue with the fan constantly on. The coolant level was topped to the very top, I expected it would drop a bit through the system after driving. I pulled fuse 57,60 and put it back, which probably did nothing, but then I turned the truck on, revved it over 2k rpm, put the E-brake on and put it in neutral. After running for about 5,6 minutes the fan kicked off and my cooling gauge finally worked again, it shot up just short of the very middle.

Solved.

I didn't replace anything, if I wanted all that I would've bought a ford.

 

[Ruthless08]

After 3 thermostat changes including adding gallons of coolant and countless web searches with no results at all and having to disconnect the battery every where I went to reset it after so many years, i finally figured out to make it work again and till now it hasn't acted up, in my case is a 2008 Chevy Silverado 2wd LT, disconnect the positive battery cable, locate the BCM which on my model vehicle was located to the left side of the brake pedal, disconnect tha connectors that plug into the BCM module one by one, and wiggle tha wires that go into tha connector gently as your pushin them in softly manner and then plug then back in, repeat tha process to the other ones as well, there's 2 fuses 25 amp each in the middle of the BCM take them out, inspect them and make sure they're not popped and then plug them back in, next step I took was to locate the temperature sensor in the engine bay, disconnect it and checked for fry and/or loose cables without removing the sensor, plugged it back in and reconnected the battery cable, went to turn on my truck, drove it and my temperature gauge went up to 210 without fluctuating up and down like it did before and engine hot/Ac turned off disappeared and it's been working sinced, I hope this was helpful and gud luck

 

[nestle239]

Thanks for info.

Since this first happened, all I do to avoid it now is let the truck warm up before driving off. I let it run until the dial reaches at least the quarter mark indicator, half way to 210 degrees/middle of gauge. If I drive onto a highway before letting it warm up it's sure to get stuck again, and I would have to rev it up to 4k rpm to get it hot enough for the temperature gauge to go back to normal, instead of staying stuck at zero with the annoying fan on and scary light.

 

[Elrowan]

nestle239

I was having same issue, did everything you said and it worked.

 

[badbruin44]

I just had the same problem but checking and reading your posts has anyone done any thing other than wiggling wires? I did see someone change thermo stats or sending unit? Let me know what was done to fix. I am thinking thermo stat or sending unit or if all fails the water pump. I did get home and let it cool down as it was running hotter than usual and started for a bit and it did some weird stuff the engine ran up to around 4K rpms and settled down but definitely funny things> Let me know if and how it was resolved thanks read info 08 2500 6.0L.

 

[ffemtmcd]

Hey all - had this problem pop up on my way home from work last night - after some research and starting with the cheapest solution first - I unplugged the temp sending unit and uncovered the wires and untaped them to check them, noticed some wear on the wire jacket. retaped as close to plug as I could get and taped up from there then recovered with the loom. 2 long drives later, no issues. will let you know if it pops back up

 

[badbruin44]

I just had the same problem but checking and reading your posts has anyone done any thing other than wiggling wires? I did see someone change thermo stats or sending unit? Let me know what was done to fix. I am thinking thermo stat or sending unit or if all fails the water pump. I did get home and let it cool down as it was running hotter than usual and started for a bit and it did some weird stuff the engine ran up to around 4K rpms and settled down but definitely funny things> Let me know if and how it was resolved thanks read info 08 2500 6.0L.

I just had this issue pop up again has anyone figured this out? I don`t like throwing parts at anything without knowing how to troubleshoot. My cobalt had a VVT cam phaser on the exhaust side give me an engine light and after googling around I found that this part has to be within 5-12 ohms which was way out of range changed it and all good. This is what I am wondering about the temp sending unit on truck is there a ohm range it should be within I`m assuming that the higher the ohms the hotter it would show on truck gauge and lower ohms lower temp on truck gauge. Has anyone had to figure this out it was fine since the last post didn`t do anything it just went away (fringing electronics) the wiring seems fine I will double check again just trying to pick your brains thanks in advance if anyone has any idea's.

 

[ffemtmcd]

I bought a new coolant sensor plug, rewrapped with tape and new wire loom ,(because mine was brittle and fell apart) haven't had a problem since and its been a month or so. Total about $11

 

[badbruin44]

Thanks for reply. I will inspect the sensor plug a lot better this time hopefully just that easy. Being kina intermittent it sounds a lot like this scenario

 

[shawn a]

ok i have the 07 silverado 5.3 new body. i'm going through the same issue motor hot a/c turned off. well i have replaced before all this started replaced the rad cause it was cracked replaced the temp sensor and the stat. and still having the problem now i don't even have to have the truck running and fans start full and says redused power. took it to a dealer i was told my dash cluster is sending faulse codes/signals to the ecm. waiting tell wed. to have the new cluster put in and programed to the truck. i will repost after

 

[Collinsbuilders]

I have had this problem on my 09 Chevy truck. It happens every time if I get on the highway before the tuck is at it's normal operating temp(~190). Not a problem just driving around town which is my normal diving schedule. If I'm getting on the highway first thing I always have to make sure it's warmed up first. If it wasn't warmed up an I got on the highway and this happened I would just pull over and disconnect the battery for a min and let it reset itself and be on my way. If I continue to drive without resetting it the extra cooling fan stays running and it seems like I use way more gas. Just waiting for the day when it's a true reading and I continue to drive(thinking it's a false reading)till I can pull over and I blow a head gasket. Hope this helps because it is not a fix, just a run around but have save a lot money not changing water pump ,thermostat... until it's a true reading