MotorBiscuit just posted earlier today about the 2020 C8 Corvette engines breaking valve springs. This post is about, yet, another problem Corvettes and other GM cars are facing. This involves GM vehicles experiencing brake sensor contamination leading to other problems. Because of this GM has issued a “stop delivery” order over the brake issue. It will lead to a recall although the NHTSA does not show it on its website yet.
The brake issue is affecting more than just the 2020 Corvette
The other affected GM vehicles are the 2020 Cadillac CT4, CT5, XT4; 2020-2021 Buick Encore GX, and 2021 Chevy Trailblazer. Here is what GM says: “Material used in a sensor connection in the electronic brake boost system in these vehicles may have been contaminated during the material supplier’s production process. Contamination of this material may cause an interruption of communication between the sensor and the brake boost system under certain conditions.”
Every component within each vehicle communicates to the ECU. Even the door handles communicate, so the whole car works as a system with each component communicating thousands of times every minute. When one of those components stops communicating it can affect the entire system leading to issues.
All of these GM cars feature brake-by-wire braking systems. That means there is no mechanical link to the brake system in these cars. The master cylinder, vacuum booster, vacuum pump, and electronic brake control module are combined as a single unit. If one part of that unit stops communicating with the brake system then the electric brake boost assist stops.
If there is a brake issue a warning light comes on
When that happens the vehicle could require more brake pedal force by the driver to stop the car. GM told the Corvette Action Center that a warning light and message come on the instrument panel if this occurs. The vehicle speed may also be reduced. The stop delivery order is the first step in correcting the issue. It is expected that GM will issue a recall for this.
When there is a recall it will be the second one issued for the 2020 C8 Corvette. The first was for the frunk lid opening while the car is being driven. This came after some quality issues surfaced which were quickly addressed.
There will probably be a recall for this and the issue we posted about earlier today
The post that MotorBiscuit issued earlier today is also expected to be a recall. This issue deals with valve springs in the Corvette’s engine braking; sometimes within the first 100 miles of use. It is also affecting all V8 engines installed between June first and September 15 this year.
So we keep watching as the issues with the new mid-engine Corvette continue to mount. We understand that there can be first-year problems that didn’t crop up during testing. This can be a common problem with first-year models. But the Corvette is really GM’s flagship and showcase for its engineering and quality. We hope to see this latest problem become the last issue we report on.