Code AC Off

[Calamitygirl]

Code: AC Off flashed one time on the way home. The thermostat needle did not budge from "L" and I was highway driving for a solid 40 minutes. No more warranty on Solar, she recently turned 100,000 (I can't believe it). 2008 H3 Adventure package.

Is changing the sensor easy like changing a fuse? Or bite the bullet and take it to the dealer?

 

[Hunner]

Go some where and have the codes read. See what it says.

Have it cleared and watch to see if it re-occurs.
Auto Parts stores usually do this for free.

 

[Calamitygirl]

Ok thank you. Went to HUMMER service but they were swamped. Said ok to drive have appt. for Monday. Temp gauge seemed to work whenever I was driving today. Code never came on. Than you Hunner, will let you know what happens!

 

[Humvdood]

Ok thank you. Went to HUMMER service but they were swamped. Said ok to drive have appt. for Monday. Temp gauge seemed to work whenever I was driving today. Code never came on. Than you Hunner, will let you know what happens!

Calamity, I see you're from Arlington.
I'm a mechanic down here in Burleson. Woot Woot DFW!!!
Do what Hunner said and have it flashed.
If it comes back and the temperature gauge still doesn't move you'll probably need a new temperature sensor.
The sensors are easy to change with the correct tool - you'll need to drain the coolant first, and since you'd be doing that, if you haven't already changed out your thermostat at 100,000 miles I'd recommend doing that. you can get the thermostat and temperature sensor both for $40 on Amazon (both are amazon prime eligible too).
I'll be out of town these next two weeks or I'd say bring it to me but if you're looking for reputable service in the area I'd recommend American Muscle Restoration in Burleson. The co-owner, James, has owned a few H3s and is very familiar with them - more so than me. If you're wanting to do it yourself, I'm sure there are dozens of us on here who could walk you through the how to's since it's one of the more common H3 issues.

 

[Calamitygirl]

On my way to have codes checked right now. Will let you know and thank you for all the valuable info! I knew exactly where under shop is!

 

[Calamitygirl]

Went to Auto Zone. No history of any codes showing! Temp gauge working fine so I'll just keep an eye out for now! Big thanks to Hunner and Humvdood!

 

[Calamitygirl]

Code is back. Temp gauge works one day then inop. Check engine light is on! Checked the obvious, gas cap. Going to American muscle car restoration on Friday to see James and hopefully get things fixed up. Thank you Humvdood for that. [emoji1]

 

[Chook]

Hey Calamity........... I had exact same fault/symptoms. I reset the codes with my ScanGaugeII & the Temp Gauge & A/C would work fine but the fault would come back.

Mine turned out to be I had fitted a set of extractors/headers and ambient was getting too hot under the hood. I had a new heatsheild made & problem went away for good.

Sounds like mine the sensor read too high & therefore designed to turn off the A/C to reduce the heat under the hood but a faulty sensor should fault to the fail state so that is likely your problem if you havent modded under there.

 

[Gunner_45]

Any word on what is up with your truck yet?

 

[Calamitygirl]

Ok, I drove way cross town this AM to see James at American Muscle Car Restoration. He seemed surprised to see me, but then he remembered. LOL So there have been no codes for the last few days and the check engine light has not come on (that happened for a few days as well).

He said can't do anything unless its actually throwing a code.

Ok, I understand that, but shouldn't he have put the meter on that reads the codes to see the history of it throwing any codes? Well he didn't and my bad I didn't ask him to. So I left and he said call me when it does it again. Then bring it back. ARGH

I stopped at O'Reilly's had them put them put the meter on and yes there was a history of a code!
PO128 (generic)
Cooland thermostat
Coolant temp Below Thermostat regulating temperature)

which we pretty much knew from what you guys had said, etc.

So I bought a coolant sensor and came home! :roll:

 

[Humvdood]

Ok, I drove way cross town this AM to see James at American Muscle Car Restoration. He seemed surprised to see me, but then he remembered. LOL So there have been no codes for the last few days and the check engine light has not come on (that happened for a few days as well).

He said can't do anything unless its actually throwing a code.

Ok, I understand that, but shouldn't he have put the meter on that reads the codes to see the history of it throwing any codes? Well he didn't and my bad I didn't ask him to. So I left and he said call me when it does it again. Then bring it back. ARGH

I stopped at O'Reilly's had them put them put the meter on and yes there was a history of a code!
PO128 (generic)
Cooland thermostat
Coolant temp Below Thermostat regulating temperature)

which we pretty much knew from what you guys had said, etc.

So I bought a coolant sensor and came home! :roll:

Yeah, me, James, and another mechanic all tore into my H3 over the last 3 weeks trying to figure out my issues.
We are all three ASE certified and have almost 100 years of combined mechanic experience but we seriously can't pin-point exactly why my a/c is retarded.
The other mechanic has the $4000 tech 2 tool which tells us everything about the system but all it's saying is my compressor isn't getting enough voltage to turn on. I can give it the 5v logic it want's and it'll kick on no problem but as far as it turning itself on, I've been SOL.

If I follow the gm protocols on this thing it pretty much (I'm exaggerating) says replace crap until it starts working.
But I can't bring myself to just start throwing money at it until it goes away.