Over-the-air upgrades (OTA) have become a popular talking point ever since Tesla debuted the feature on the Model S, so it’s no surprise that Chevrolet has added the capability to the new C8 Corvette. While OTA upgrades should save some trips to the dealer for small software reflashes, they also bring more complexity for those tinkerers that want to modify the factory computers.

Allowing OTA access to any vehicle requires better security and encryption, and the Corvette system will be no different.
The basis of the electrical system in the C8 is the brand new General Motors “Global B” architecture.
It comes with a variety of computers, such as the E99 engine control module that plugs into it.

This increased level of security yields PCMs that have stronger encryption with fluid coding that is VIN-specific and harder to crack.
Many of the modules require a piece of code from the GM side in order to be modified.

This development makes it harder for tuners to change the code in the PCM.
They don’t have the other piece of the puzzle the calculation that is done on the GM side to verify that the code in the PCM calculates out to a valid checksum.
Some have made claims that this will render the new Corvette “un-tunable” by the aftermarket, but as 1 magazine claims pointed out a couple of months ago, the electrical architecture and PCMs are not necessarily completely tied together and although they are symbiotic, they can still be modified separately.

Luckily, GM decided to test this new E99 PCM before the C8, when it was installed in the 2019 C7 ZR1.
In hindsight this seems like a smart play, as it allows GM to get data back on the PCM from a lower-volume model before it spreads it to the whole line.
A nice side effect, too, is that the aftermarket got a head start to crack the code.

While the E99 PCM cannot be directly programmed like previous GM PCMs, there are ways to get into it, as already proven by some tuners.
Working on the E99 PCM as soon as the ZR1 was released and after some attempts at cracking the code, they found a way to reflash the PCM to accept changes from their software.
This of course voids the car’s GM warranty and could cause a high fine by the feds as this has violated law as to smog laws.

These re-flashes cannot be completed on a stock PCM, given the risk the system could possibly be bricked, so customers will require a specially modified PCM ordered from tuners if they want to get crafty.

The specially modified PCM adds around $2000 to the tuning cost if you’re sending your original unit to them as a core, or $2500 if you want to keep your PCM.
The notes on the modified PCM state that it can only be modified with software and tools so it’s probably a wise decision to keep the original PCM in case you want to return the vehicle to stock condition or enable updates from GM.

In addition to the PCM cost, the software license requires additional license cost, the cost of the tuning software, plus the cost of $500 plus of what a tuner will charge for the tune itself.

Once the modified PCM is received from a tuner, it still requires a few extra steps (and possibly a visit to the dealer), as the engine immobilizer is tied to the PCM and installation requires an immobilizer relearn by the GM dealer tool.
Luckily, the relearn functionality is also available through the Service Programming System (SPS) which is available to independent shops and individual for those that don’t want to flatbed their Corvette over to a Chevy dealer.

In the end the above once the tune is done and the stand alone PCM will set you back about $4,000 and if that PCM breaks you would have to start the process all over again
Those that wish to use the new LT2 engine as a swap in another application shouldn’t be worried about these costs
it is very likely that GM will release an PCM kit once the engine is available in crate form.

An PCM kit is already available for the LT5 engine from the ZR1, which contains the aforementioned E99 PCM, so it is likely that the LT2 engine might be cross-compatible with that crate engine PCM kit at some point.
The standalone PCM kit may be a consideration by some Corvette owners but it cannot be used in OEM applications as it is not meant to interface with the other modules in the car and is only intended for use in swaps for other vehicles.

In short term do not intend to do any mods with your C8 until IF a proven and save way to get tuning done