rckt

This thread is making me rethink an HTC vs a transparent top coupe.

Pisswilly

Long term, HTC’s seem like they will be problematic.

Red rag

Bugs happen.we’re all relatively early in the C8 run and are Guinea pigs. Luckily it’s not major for OP.

DragonDeity

Got service convertible top message about five weeks ago, top worked fine 1st week of service message and stoped working the 2nd week with the top refusing to lower. Dealership mechanic first calibrated the top and got the top to lower twice before it stopped working again. End of last week service department said they ordered an actuator and additional hardware, the additional hardware arrived but the actuator is on back order. Now the middle of third week the cars been sitting in the dealership service department. I’ve had my 2021 Z51 almost 2 years now and this is the first time I experienced trouble with the convertible top.

JerriVette

I know this sounds ridiculous but humor me if you could.

do any of you guys use your key fob remote starters ever?

there is a theory that the remote starter that causes the transmissions to create the same symptoms on the dash as the htc top not working except it causes the transmission to not work.

there could be as much as a week in between using the remote starter and the htc and in other cases the transmission needs servicing.

im suggesting it’s the same cause in both types of issues.

if you get the message and disconnect the battery the negative battery terminal within the first few minutes it should keep the battery fresh enough to close the top

it’s antidotal but the same message one for the top , one for the trans.

this sucks

No fix yet long term.

don’t use your remote starter again supposedly solves the issue as long as you drive the car for an hour on the highway to. Rejuice the battery. Do NOT use the remote starter would be a possible solution if that’s the cause?

I KNOW IT SOUNDS RIDICULOUS

R23HTC

I use remote start all the time. I also have the MODS4CARS module and can put the top down and up via remote. No issues with mine.

hamta

I'm not 100% certain that I fully understand the above question/response. However, I have a 2021 C8 HTC (Z51 if that matters) and I use the remote start (using my key fob) at least a coupe of times a week and I have NOT had any problems of any type with lights, codes, or any other abnormal behavior. So, I don't know if this answer helps or further complicates the diagnosis. My HTC, transmission, and entire car operates completely normally. I do use a battery tender.

I hope this helps...

brocco

Used the remote all the time without issues till now.
The Latest: Field Engineering group told the dealer to order an “Updated Top Control Module”. I know the dealer wants the car out of their shop as it’s been sitting in their shop taking up a lift since mid May, they do update me regularly. Not getting any error lights as was mentioned above, it’s just throwing error code’s basically stating a loss of communication. Not having the car sucks 🤬!

Update: Field Engineer will be onsite Tuesday / Wednesday, doesn’t want the dealer to install the “Updated” Top Control module until he can inspect the car.

Reading about a lot of cars sitting in dealerships for multiple weeks with wired problems. Seriously considering accepting the offer the Sales Manager gave me last week. But I’d probably be pissed at myself.

hill536

My update from yesterday. Tried to lower the top and was met with the service message. Drove to my destination and parked. Upon leaving used the remote to lower and it worked. REPEATEDLY.

Reading the latest posts …. Going to try NOT using the remote start to see what happens. I’ve used the remote start nearly 100% since owning.

JerriVette

I would imagine it’s only antidotal but so far we are finding some evidence of electrical gremlins from “zero engine psi, to service transmission and the htc not working correctly. Service htc.

disconnect the cars battery quickly from the negative terminal and re attach and all systems work correctly if done before the flashing dashboard drains the battery down to far.

could definitely be wrong.

I’ve had three transmissions over 25k miles ..7 to 10 k between them and just recently used the cars remote start 11 months after installing new transmission and then within the week had a reoccurring no start with only an accessory mode . Not being able to start or shut off the car. (Got service transmission and this time zero engine psi warning on dash.

bought a new battery, bought a new fob battery and within four days the no start until disconnecting the battery and reattach reoccurred. Then the car started up easily ..drove an hour to let the alternator recharge the battery

I am sharing the experiences because I believe these issues are all interrelated somehow.

I don’t think it’s the htc top system, or the transmission and sure as heck not the zero engine oil psi are the cause. GMs been great replacing the transmissions etc but I think the transmission , the htc not working and now engine 0 psi are all symptoms.

it’s a system error not a htc top , transmission or engine oil pressure system.

just trying to assist in figuring out the core issue.

so far the guys who stop and never use the remote engine start once the car is driven enough to powerfully enough to recharge the battery with the cars alternator are not seeing a repeat no start so it’s just a suggestion ..

it’s not an immediate no start on using the remote ..it’s like a week later so it might not be related but getting stuck is such a nightmare at this point I thought I’d share a minimally possibility based solely off antidotal evidence.

the corvette engineers don’t know , the techs don’t know and as owners we don’t either.

all I know is this is a real PIA.

im half thinking a anti theft kill switch to the battery installed would be a quick solution to disconnecting power quickly when these messages pop up to be able to drive before the battery gets drained.

sorry it sounds nuts but it’s 50 or 60 times occurring for me. Three transmissions and no resolution from corvette engineering yet that’s permanent. So far the most miles is 10k and 11 months with no problem. Used the remote start a couple of weeks ago for the first time in that 11month 10k period and now the no start stuck in accessory mode can’t turn the cars dash off situation until quickly disconnecting the battery to get the car to reboot its system.

I believe these symptoms we are experiencing are related with a root cause .

just my opinion as a layman of course in this field.

brocco

Finally got the car back today, the Field Engineer found pin tension on the X331 Folding Top Control Module was loose causing a short. The X331 harness and Left Folding Top Control module were changed. Took the car for a VERY spirited drive and all is well with zero rattles!

Now let’s see how GM Customer Service will compensate me for not having my car for over a month.

Service Advisor mentioned 2 other HTC’s are in the shop for their tops not working, pattern here?

MillerTimeISU

I am understanding this that you think the key fob remote start is potentially tied to all these issues 🤦‍♂️

brocco

I appreciate everyone’s input here and respect their thoughts, but in my case use of the key fob had no relationship to the HTC failure.
Actually, I don’t see the connection to key fob use and mechanical breakdown. GM uses similar fob technology across many of its car lines which would lead me to believe that there’d be more failures on the same.

I'm just happy to have my car back after over a month of it being in the shop… even though it’s been raining in NJ since I got it back 🤬

MillerTimeISU

Can you give an idea on what the sales manager offered for buy back?

brocco

Low 80’s initially, the day I picked the car up, increased to mid 80, also mention he has a Z06 coming in but they play the “Market Availability” mark up game which is horse sheet.

lion shf

Can you ask GM what this would cost out of warranty please? I’m gun shy to own this car out of warranty because of this issue and the transmission.

brocco

my suggestion is to purchase an extended warranty, very cheap price to pay for peace of mind monetarily. These cars are too fun and exciting to worry about possible breakdowns. Things will break, things will get fixed.

RKCRLR

The Chevrolet Platinum Protection Plan excludes the convertible top framework so that likely wouldn't be covered unless it was somehow caused by other top components that are covered. Other service contracts may cover convertible top framework but you would need to read the fine print.

Edit: I was thinking of a different thread. The issue in this thread would be covered.

brocco

in my case it was all electronic module, wiring harness related

RKCRLR

Oops, wrong thread. I was thinking this was the thread with the cracked bracket. Yes, convertible top electrical components, sensors, motors, modules, wiring, etc. are covered under the Platinum plan.