Why the 2021 Corvette has a warning light for diesel glow plugs

When the Corvette C8 came out, it fulfilled one of the Corvette’s two longtime big dreams: a mid-engined “Vette”. That other dream, I think we would all agree, is the dream of a smoky, slow diesel Corvette. Right? What Corvette fan hasn’t dreamed of this? This diesel dream seems to have an unexpected ray of hope, thanks to an eagle-eyed person who spotted a diesel glow plug warning light on a C8 dashboard. But don’t get too excited just yet. Just be prepared to be confused.

It all started when I was alerted to this post on the Reddit r / Cartalk forum, where a user named RefrigeratorRunner posted an image of a 2021 Corvette instrument cluster, a close up of the warning light panel showing what is clearly the icon for a diesel glow plug:

Eh. Check it out. Just to make sure someone wasn’t having a bit of fun with Photoshop, I looked for other photos of the C8 ‘Vette dashboard to confirm, and, yes, it’s there (I zoomed in and highlighted the shape, but you can see it next to the arrowhead):

I also checked owner’s manual, and it’s not mentioned here, which makes sense, because if that ever happened, it would somehow mean your entire engine was swapped out for a diesel engine with glow plugs.

Baffled by why a car without glow plugs would have a warning light for those non-existent spark plugs, I reached out to GM for answers. I asked why the light was there, and if that was a clue to a future diesel Vette. Here is what they replied:

We appreciate speculation, but this symbol has been included as part of our standardization process. This does not indicate any plans to add the feature to Corvette and we plan to remove the icon in the future.

Okay, so no one is kidding, that symbol is there on the dashboard! And GM has no plans to add glow plugs to the Corvette. Good to know.

But I still had questions. It’s not like the C8’s dashboard has just been removed from the GM parts bin – it was designed very specifically for this car.

Why would the designers of the Corvette instrument cluster include an icon for a warning light for a component that GM had absolutely no intention of including on the car? It was the answer:

It’s an internal GM process when we sell cars in international markets.

Alright, good. But not really well. I can’t stop thinking about this. Is there a rule in this internal process for international markets that states that all cars must have all possible dash light symbols, regardless of whether that particular car will never use this warning light? ? Should GM electric vehicles have catalytic converter warning light symbols, for example? What’s the rule here, what’s going on, why is it like this?

I got this response:

Jason:

Sometimes we plan to share some of the displays between vehicle programs and therefore standardize the icon locations.

The tone of this “Jason:” part made it seem like the PR rep was annoyed and pissed off by my incessant questions about ridiculous and irrelevant bullshit, but I can’t help myself. Each answer only introduces more questions!

He said “sometimes we plan to share some of the displays between vehicle programs” – does that mean GM is really considering a diesel car in the international market that could use the instrument cluster from a Corvette? Will there be a new Chevy Sail Diesel in the Indian market that could use this dashboard? Or a GMC Yukon diesel from the Chinese market with a Corvette instrument cluster?

I can answer these questions: no. Hell, no, even.

There is no way in our understanding of the universe that GM is going to use this particular instrument cluster in anything other than a Corvette, especially not in anything with a diesel. And there’s even less chance of a Corvette going out with a 2.2-liter diesel four sitting behind the seats. These are just not things that are going to happen.

And I’m pretty sure anyone who has been involved in the development of the Corvette C8 knows this. And yet somehow one instrument cluster designer took the time, however minimal, to include this little outline of the glow plug symbol on this indicator light strip.

They had to adjust the spacing and size of the other lights to make sure they fit. It has been screen printed or otherwise on the plastic panels that form this part of the display.

Does the glow plug light have traces on this circuit board for components to turn it on? Does it have the components themselves? I haven’t found a photo of the bare PCB online to view yet, and I don’t have access to a C8 to take apart, so I just don’t know. How far does it go?

I know GM is a business and like all businesses there are some absurd rules that just don’t make sense but exist anyway. I understand that. But that doesn’t mean it’s not at least a little bit of madness.

And when the GM rep said

we plan to remove the icon in the future

… that makes it even more Following absurd! I mean, it’s crazy already that they design and build a car with a warning lamp symbol (and maybe more material) that it was never intended to use, but it makes same less meaning to take the time and effort to remove it later.

It’s barely visible. It will never light up. It’s already there. Why waste more time and effort to get rid of it?

I know I’m a little obsessed with this, but I can’t help it. What if the designer of the instrument cluster had just, you know, left out the non-existent light symbol, to warn of parts that don’t exist? Would an inspector have noticed this and halt the process until the designer goes back and includes the symbol? Knowing that every action taken would have absolutely no fucking difference to the resulting car?

Would the process have been? If yes, why? And if not, then why is that fucking symbol still there?

It haunts me. GM, why are you like this? Can’t you see what you’re doing to me?