[carguy83]

This morning as I adjusted my climate control hvac settings, the only thing displayed on my 8" screen was a large grey bar with the small letters reading "ac on" or "ac off" (depending on what I set). Normally it shows a picture of the corresponding button, blend/defogger etc etc. Anyone else have this issue or know the fix? I'm at 1600kms

[carguy83]

Update: car sat at work parking lot for 8 hours. I came out and started it and hvac modes are once again acting normal, by flashing current setting on the screen. Unsure of why this occurred today but as of right now it's all good

[StormBlaze]

My car does this randomly as well, haven't bothered to go to the dealer about it as it usually sorts itself out on a restart later on in the day.

[DrRedD]

i get this too - seems to happen if i use the remote start - found this: http://gm.oemdtc.com/5176/intermitte...-dis#more-5176

Taking it into dealership to get all the software refreshed/updated on Saturday.....

[JaxChris]

Random issue in the display interface between the HVAC control module and the MyLink. If it bothers you (e.g. you're on a long drive), pull over real quick and restart the car to clear the problem.

[Slayer_TauNu]

I get this issue pretty frequently on my 2017. Appears to only happen when I use the remote starter. Will have the dealership check the software when I get my 1st oil change. But this TSB says there is no solution yet: https://static.nhtsa.gov/odi/tsbs/20...99144-2280.pdf

[PnCRedJwl2SS]

Originally Posted by carguy83

This morning as I adjusted my climate control hvac settings, the only thing displayed on my 8" screen was a large grey bar with the small letters reading "ac on" or "ac off" (depending on what I set). Normally it shows a picture of the corresponding button, blend/defogger etc etc. Anyone else have this issue or know the fix? I'm at 1600kms

In most cases, this happens with A8 cars when remote starting. I have found that it seems to be a systems startup up timing/sequence issue. By unlocking the doors using my key fob first, then locking the doors, and THEN remote starting it, I’ve eliminated the problem every time. I never have the problem with the HVAC controls or with any drive mode settings disappearing. And now I remote start with confidence every time.

Give it a try!

[soldes]

I've been following that advice for a few weeks now and the man is right!
Normal remote start : grey bar 90% of the time, with unlock lock remote start 100% hvac control display

[Eldi Z]

Since I encountered the same issue with my 2017 SS 1LE, I searched and found this thread.
I do not use / have remote start.
To me it happens occasionally, however, the workaround I found is to start the engine only after first pressing the Start button for ~ 10 seconds (going into active ACC mode) without engine actually starting (by not pressing the Clutch pedal...in Autos this would be not pressing the Brake pedal).
Only then, I press Clutch and Start button to start the engine as usual.

I do not think that the community should tolerate glitches like this and resort to workarounds (having to unlock/ re-lock doors before starting; go into ACC mode first).

Does anyone know if GM already has a permanent fix to this issue?
Firmware update of the HMI / HVAC-CM/ B-CM?
TSB ?

[PnCRedJwl2SS]

Originally Posted by Eldi Z

Since I encountered the same issue with my 2017 SS 1LE, I searched and found this thread.
I do not use / have remote start.
To me it happens occasionally, however, the workaround I found is to start the engine only after first pressing the Start button for ~ 10 seconds (going into active ACC mode) without engine actually starting (by not pressing the Clutch pedal...in Autos this would be not pressing the Brake pedal).
Only then, I press Clutch and Start button to start the engine as usual.

I do not think that the community should tolerate glitches like this and resort to workarounds (having to unlock/ re-lock doors before starting; go into ACC mode first).

Does anyone know if GM already has a permanent fix to this issue?
Firmware update of the HMI / HVAC-CM/ B-CM?
TSB ?

Even though you drive the M8, I'm curious if just unlocking with the key fob, then locking again with the fob, then unlocking with the fob will do the trick for you. If it does, at least you can avoid waiting the 10 seconds before every start...I'm thinking this electrical activity will "wake up" the car systems so they will start up in the correct sequence.

Try it and let us know!

[Eldi Z]

Originally Posted by PnCRedJwl2SS

Even though you drive the M8, I'm curious if just unlocking with the key fob, then locking again with the fob, then unlocking with the fob will do the trick for you. If it does, at least you can avoid waiting the 10 seconds before every start...I'm thinking this electrical activity will "wake up" the car systems so they will start up in the correct sequence.

Try it and let us know!

Yep. Let me try this sequence and check for consistency in terms of what the screen shown when operating the AC.
I shall report back my findings after a couple of weeks of testing this.

[Eldi Z]

Originally Posted by Eldi Z

Yep. Let me try this sequence and check for consistency in terms of what the screen shown when operating the AC.
I shall report back my findings after a couple of weeks of testing this.

Seems like this sequence of locking-unlocking actually works, however, it is annoying that I must rely on such measure for it to work properly.
Last night I forgot to do it and had the disappearing screens of HVAC and Driver Modes in the settings

Has anyone so far actually had the dealer update the FW to make it work as it should?