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Temperature gauge drops to full cold, check gauges light comes on??

1907 Views 20 Replies 9 Participants Last post by  Chewy19
2008 Envoy Denali with 120k mi in excellent well maintained condition. Problem started a few years ago, first time it was hot out and of course the AC quit blowing cold and the check gauges light came on. Pulled over and checked under the hood all was OK. Did the basic checks and found nothing. Engine code for engine not warming up fast enough. Monitored system with scan tool and all looked fine and temp gauge worked. Did the Google and the general opinion then was thermostat so I put a thermostat in and serviced the cooling system. Everything was fine for a while and here we go again. Did the whole deal over again this time with a factory thermostat. Again monitored the system and all functioned just fine. Did the cluster control function and all was good as the new Google searches went from thermostat to stepper motor. Did some research and saw that the BCM would default the gauge to cold if it was told that the temperature didn't warm up fast enough which I guess it compares IAT to coolant temp. I now carry a 5/16 battery wrench so when it happens and I'm out and about I can disconnect the battery and get the system functioning again so I have AC. More Googleing and I'm still getting dead ends and wild guesses and no fix but plenty with the same complaint. My theory is the PCM needs an updated program to stop this BS but I don't have any contacts in the dealerships any longer.
Has anyone found a fix for this? I see on this forum it's still an ongoing complaint but I don't see a fix.
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I'll help you ... but you have to break that post into sentences, paragraphs and periods followed by Capitol letter.

Otherwise TM/WR ....... or -----> too messy~won't read.
When I look at the post it has sentences, punctuation and capital letters.
Short version, Temperature gauge goes full cold after driving. Check gauges light comes on and air conditioner stops working. Disconnect battery and everything works.
Disconnect battery and everything works.
You do WHAT?

YOU DISCONNECT THE BATTERY?

WHEN DO YOU DISCONNECT THE BATTERY?

DO NOT TELL ME YOU DISCONNECT THE BATTERY WHEN THE ENGINE IS RUNNING

--- DON'T EVEN SAY IT!
This is [email protected] ....
2008 Envoy Denali with 120k mi in excellent well maintained condition.

(no definite article, -10pts) Problem started a few years ago, (should be a period here -5 pts)

(no cap = - 5pts)
first time it was hot out and of course the AC quit blowing cold and the check gauges light (mixed plurality - 15pts) came on.

(no subject of the predicate - 25pts) Pulled over and checked under the hood (poor continuation of the sentence - 25pts) all was OK.

(no subject of the predicate - 25pts) Did the basic checks and found nothing.

Engine code for engine not warming up fast enough (incomplete sentence - 20pts).

(no subject of the predicate - 25pts)
Monitored system with scan tool and all looked fine and temp gauge worked.

(no subject of the predicate - 25pts)
Did the (? - 10pts) Google and the general opinion then was (a definite article is needed here -10pts) thermostat so I put a thermostat in and serviced the cooling system.

Everything was fine for a while and here we go again.

(no pronoun to define the subject of the predicate - 25pts) Did the whole deal over again this time with a factory thermostat.

Again (needs an object of the predicate -10pts) monitored the system and all functioned just fine.

(no article for the predicate - 25pts) Did the cluster control function and all was good as the new Google searches went from thermostat to stepper motor. (clumsy sentence -10pts)

(no article for the predicate - 25pts)
Did some research and saw that the BCM would default the gauge to cold if it was told that the temperature didn't warm up fast enough which I guess it compares ("the" article needed here - 2pts) AT to coolant temp.

I now carry a 5/16 battery wrench so when it happens and I'm out and about I can disconnect the battery and get the system functioning again so I have AC.

More Googleing (poor gerund and spelling error, 3pts) and I'm still getting dead ends and wild guesses and no fix but plenty with the same complaint.

My theory is the PCM needs an updated program to stop this BS but I don't have any contacts in the dealerships any longer.

Has anyone found a fix for this?

I see on this forum it's still an ongoing complaint but I don't see a fix

So --- that's sortta fixed for ya.

Your score is
-230pts.


(signed) Your Local Grammar Nazi
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Have you ever replaced the ignition switch module? Lots of gremlins have been exorcised by replacing that module. I had the dash light up like a Christmas tree, plus oil pressure gauge, fuel gauge, and engine temp all dropped to zero, cruise control didn't work, XM radio, heated seats, HVAC didn't work while driving at 75 on the highway. Replaced the module, all better.
I don't know the cause of your error, mine was thermostat. But I suggest getting an inexpensive ODBII reader (maybe a bluetooth model that talks to your phone?).
When you erase the P0128 error you will see the temp gauge come up, as well as your a/c. No need to remove battery connection to get a/c working again.
I have changed the thermostat twice. I have access to a Snap On Modis. I disconnected the battery when I was away from home and wanted the AC back on.
I disconnected the battery when I was away from home and wanted the AC back on.
......................... no comment ...............
The most triggering words we see on this forum:

"I disconnected the battery."

Loading the parts cannon in 3.2.1.
I have changed the thermostat twice. I have access to a Snap On Modis. I disconnected the battery when I was away from home and wanted the AC back on.
I keep the small OBD in the car.
Side note, there seems to be a high percentage of commenting SS that helps no one with their car issues.
change 'coolant and temp ' sensors before changing thermostat ,so many errors are not thermostat related
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2008 Envoy Denali with 120k mi in excellent well maintained condition. Problem started a few years ago, first time it was hot out and of course the AC quit blowing cold and the check gauges light came on. Pulled over and checked under the hood all was OK. Did the basic checks and found nothing. Engine code for engine not warming up fast enough. Monitored system with scan tool and all looked fine and temp gauge worked. Did the Google and the general opinion then was thermostat so I put a thermostat in and serviced the cooling system. Everything was fine for a while and here we go again. Did the whole deal over again this time with a factory thermostat. Again monitored the system and all functioned just fine. Did the cluster control function and all was good as the new Google searches went from thermostat to stepper motor. Did some research and saw that the BCM would default the gauge to cold if it was told that the temperature didn't warm up fast enough which I guess it compares IAT to coolant temp. I now carry a 5/16 battery wrench so when it happens and I'm out and about I can disconnect the battery and get the system functioning again so I have AC. More Googleing and I'm still getting dead ends and wild guesses and no fix but plenty with the same complaint. My theory is the PCM needs an updated program to stop this BS but I don't have any contacts in the dealerships any longer.
Has anyone found a fix for this? I see on this forum it's still an ongoing complaint but I don't see a fix.
This is [email protected] ....
2008 Envoy Denali with 120k mi in excellent well maintained condition.

(no definite article, -10pts) Problem started a few years ago, (should be a period here -5 pts)

(no cap = - 5pts)
first time it was hot out and of course the AC quit blowing cold and the check gauges light (mixed plurality - 15pts) came on.

(no subject of the predicate - 25pts) Pulled over and checked under the hood (poor continuation of the sentence - 25pts) all was OK.

(no subject of the predicate - 25pts) Did the basic checks and found nothing.

Engine code for engine not warming up fast enough (incomplete sentence - 20pts).

(no subject of the predicate - 25pts)
Monitored system with scan tool and all looked fine and temp gauge worked.

(no subject of the predicate - 25pts) Did the (? - 10pts) Google and the general opinion then was (a definite article is needed here -10pts) thermostat so I put a thermostat in and serviced the cooling system.

Everything was fine for a while and here we go again.

(no pronoun to define the subject of the predicate - 25pts) Did the whole deal over again this time with a factory thermostat.

Again (needs an object of the predicate -10pts) monitored the system and all functioned just fine.

(no article for the predicate - 25pts) Did the cluster control function and all was good as the new Google searches went from thermostat to stepper motor. (clumsy sentence -10pts)

(no article for the predicate - 25pts)
Did some research and saw that the BCM would default the gauge to cold if it was told that the temperature didn't warm up fast enough which I guess it compares ("the" article needed here - 2pts) AT to coolant temp.

I now carry a 5/16 battery wrench so when it happens and I'm out and about I can disconnect the battery and get the system functioning again so I have AC.

More Googleing (poor gerund and spelling error, 3pts) and I'm still getting dead ends and wild guesses and no fix but plenty with the same complaint.

My theory is the PCM needs an updated program to stop this BS but I don't have any contacts in the dealerships any longer.

Has anyone found a fix for this?

I see on this forum it's still an ongoing complaint but I don't see a fix

So --- that's sortta fixed for ya.

Your score is
-230pts.


(signed) Your Local Grammar Nazi
Ravalli, what once was cute is now plain stupid. If you don't want to answer a friggin' question, don't. Your assanign responses now suck big. The folks are here for answers, not grammar school. Oh yea, if you can't read between the lines, GET NEW GLASSES!
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Ravalli, what once was cute is now plain stupid. If you don't want to answer a friggin' question, don't. Your assanign responses now suck big. The folks are here for answers, not grammar school. Oh yea, if you can't read between the lines, GET NEW GLASSES!
Sorry, I don't know how to spell ass-a-nine
Sorry, I don't know how to spell ass-a-nine
Check your tattoo.
Check your tattoo.
Wait! I got to get snacks . . . 🍿🧂🍺 OK. Continue . . .
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Wait! I got to get snacks . . . 🍿🧂🍺 OK. Continue . . .
hey dude get some chitos and fritos. be good for this "NO FACE PERSON" only the dumbest of the STOOGES. As i said earlier many places you've nothing to bringg back except a stooges face. cool dude, you're still a stupid ****!
You don't really have much of a sense of humor, do you? Around here it helps to have a thick skin. I don't like it either, but if you can't beat 'em . . .

With Rivali, you learn when it's time to just sit back and watch. Cheaper than Netflix. 😁
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You don't really have much of a sense of humor, do you? Around here it helps to have a thick skin. I don't like it either, but if you can't beat 'em . . .

With Rivali, you learn when it's time to just sit back and watch. Cheaper than Netflix. 😁
I may unblock you if you keep saying nice things about me ..... mebbee......
I may unblock you if you keep saying nice things about me ..... mebbee......
Just calls 'em as I sees 'em . . .
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