While I doubt any owners of the GMC Hummer EV are actually taking their huge six-figure toy offroading, they should be careful if they plan to ford any rivers or streams. Or, hell, even take one through a car wash. The NHTSA has sent out a Technical Service Bulletin regarding the Hummer EV can suffer electrical issues if water gets where it isn’t supposed to.
The reality is that the issue stems from a problem with the Hummer’s build quality. One area beneath the windshield and near the a-pillar is not properly sealed. If water enters through here, it could leak onto a connector which could corrode the terminals of the connector. Water leaking through that small hole could result in the controls for the driver’s side window, mirrors and door locks malfunctioning.
Or it could even get annoyingly worse. “Some customers may also report unwanted activation of the theft alarm system, or random messages on the DIC such as “service latch” the report warns.
A detailed fix for this is shown in the bulletin by the NHTSA. But it’s so complex and intensive that it should be done at a dealer. Or better yet, this should have been done at the factory while the Hummer was being manufactured. It’s honestly not surprising these kinds of quality problems are coming up. The Hummer EV was developed quickly. One hopes these kinds of problems dont find their way into the vehicle’s batteries. Like the vehicle itself, the battery tech was developed quickly. So fast that the battery tech was done before the Hummer itself was even in development.