carbuff

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Hi Guys,

Need your help please. Just took delivery of our long-awaited 2020 C8 Convertible.

The 2 keyfobs will not retract the roof nor lift the toneau cover (engine cover).
I am either doing something wrong, OR they changed the procedure (Like they did with the frunk opening sequence) or something is defective.
Can you help?

The keyfobs will unlock and lock the doors, so they are not dead.
The inside door switch will lower and raise the roof.
As the tonneau cover can ONLY be opened with a keyfob (no button inside car), I need to solve this problem.

A. To open roof (put top into trunk):
Trunk closed.
Tried with car OFF, ACC or ON (running) in "Park." Distance near or inside car.
Press and release "unlock" button on remote.
Quickly press and HOLD! "convertible" button for few seconds, waiting for something to happen.
RESULT: NOTHING HAPPENS.
Did all the troubleshooting stuff on page 44 of the manual. No help.

B. To open Tonneau cover (gain access to engine):
Trunk closed. Roof locked in up position.
Tried with car OFF, ACC or ON (running) in "Park". Distance near or inside car.
Press and release "lock" button on remote
Press and HOLD! "convertible" button for few seconds, waiting for something to happen..
RESULT: NOTHING HAPPENS.
Also tried the variant seen in the GM's 2020 Corvette Accelerated Preparation video, where they say just to: Press (NOT HOLD) "convertible" button as the 2nd of 2 steps.

Repeat all procedures with keyfob #2 - same null results.

Stuff I already know:

1. Roof can ONLY be closed via the door switch, NOT remote.

2. But tonneau can ONLY be closed via the remote.
According to page 45-46 of the manual, to close the tonneau cover:
Vehicle OFF.
Press "lock" and quickly press and HOLD! "convertible" button to start closing tonneau cover.
The remote key MUST be used (ie. they imply no way to do this via any button inside car).
Did all the troubleshooting on page 46. No help.

SOLUTION to problem:
Anyone have a convertible that can tell me what exact steps they use to work the remote control for the roof and tonneau, and is the car in on/off/acc? Thanks for your help.
 
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Murray20c8

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I thought it was the same as the frunk. Press once and then press again, but hold.
 

carbuff

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I thought it was the same as the frunk. Press once and then press again, but hold.
OK, figured out the problem. Weak car battery (not keyfob battery!).
Car would put down roof off door button, and start normally. Nothing on the DIC to indicate a weak battery.
Put a trickle charger on it overnight, and remotes work fine now.
Not sure why the weak battery.
But sure that the keyfobs require a strong, fully toped-up car battery to work the roof and bonnet on the HTC.
 

Murray20c8

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Seems many batteries arrived at the dealer in "not so good" condition. Too much time in transit or sitting in BG parking lot. Perhaps yours suffered like that.
 

netsinah

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OK, figured out the problem. Weak car battery (not keyfob battery!).
Car would put down roof off door button, and start normally. Nothing on the DIC to indicate a weak battery.
Put a trickle charger on it overnight, and remotes work fine now.
Not sure why the weak battery.
But sure that the keyfobs require a strong, fully toped-up car battery to work the roof and bonnet on the HTC.

Glad you found the solution. I had no idea why it wasn't working for you (you were doing everything correct) and of course, the most obvious solution is the one I didn't consider...
 
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ABC

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For what it's worth, I also read that there is a temperature sensor and that the roof mechanism in the HTCs will not work when it is too cold. Not sure on what site I saw that but you may want to look into that also.
 

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Tonneau: Can only be raised or lowered with FOB.
No need to be in ACC. Everything can be OFF. Must be in Park though. Press LOCK button then press and hold the roof button and hold till the operation is complete. There will be a chime. Same procedure for raising or lowering tonneau.

Roof:
To open with FOB: No need for ACC etc. Must be in Park. Press Unlock then Roof button and hold till done=Chime
To open in cabin: Press and hold roof button till done=Chime
To raise.. can only be done in cabin. Lift and hold roof button till done=chime

Roof will not go down if too cold.
 

AndrewJ

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Seems many batteries arrived at the dealer in "not so good" condition. Too much time in transit or sitting in BG parking lot. Perhaps yours suffered like that.

I noticed the same when my car was delivered and I plugged in the "Corvette" trickle charger... that it was only charged to the first bar...was fine the next am..
 
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Murray20c8

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Not sure about modern cars, but when winter storing my 98 Camaro I would lock the car manually, remove the battery and bring it inside. In the spring it would only take a few minutes for the computer to relearn.
 

carbuff

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"Roof will not go down if too cold."

Anyone know how cold is "too cold" for dropping the roof?
 

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carbuff

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That answers the question. Thanks for the help and link!
 
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Corvette-North

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That answers the question. Thanks for the help and link!
Question, I picked up my 2021 HTC on Friday. Dealer tinted the windows. Waited the required timeframe before operating the windows, no issues.
Trying to lower the top from remote or from inside drivers side console. Nothing works. Would they have pulled the fuse to be safe and forgot to put it back in?
Reading the manual but no indication why it would not work from inside the car with the engine running in park. Anyone have any ideas ?
 

carbuff

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It SHOULD work.

Inside button works whether the car is on or off. In park or in drive gear.

Battery has to be FULLY charged for that to work. Maybe battery was drained in the process.
Even a 1 VDC drop can cause that to not work.

Charge up to 100% and try again to see if that fixes things.
 
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Corvette-North

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It SHOULD work. Something is wrong with your car.

Inside button works whether the car is on or off. In park or in drive gear.

Battery has to be FULLY charged for that to work. Maybe battery was drained in the process.
Charge up to 100% and try again to see if that fixes things.
Took car out for an hour drive, using the button to lower from the drivers side console, engine still on, still not working.
 

carbuff

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Are you pressing DOWN on the door button, and HOLDING DOWN for a few seconds?
You need to keep pressing the button all the way thru the cycle.
Still does not work doing that?

Easy way to remember the direction for everyone reading this is to: press DOWN for roof DOWN, and pull UP for roof UP.
 

Corvette-North

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Are you pressing DOWN on the door button, and HOLDING DOWN for a few seconds?
You need to keep pressing the button all the way thru the cycle.
Still does not work doing that?

Easy way to remember the direction for everyone reading this is to: press DOWN for roof DOWN, and pull UP for roof UP.
Held the power down button for 20 seconds, and the it worked for the first time. All good, thanks.
 

carbuff

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Awesome! Glad I could help.:Hurray:
 
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