General Motors is asking all owners to make an appointment with one of their service technicians for a preventative measure related to the car’s high-voltage battery connector. It’s not a recall, GM clearly states, as the automaker has essentially moved to act before the National Highway Traffic Safety Administration could get involved. Rather, the Hummer manufacturer callsthis a “Customer Satisfaction Program.”

Say what you will about that wording, but here’s what’s happening: an estimated 424 Hummers and BrightDrop EV600 vans may suffer from corrosion of that connector, inviting water to seep into the high-voltage battery pack, writes. Should that happen, the vehicle’s instrument cluster display should alert the driver to the issue. The potential ramifications haven’t been disclosed, but water and electricity mixing have been known to result in customer dissatisfaction.

The solution is simple: apply sealant. That’s what a GM tech will do when you bring your Hummer in. If you happen to be one of the first Hummer EV owners and aren’t sure if your truck needs that service, you can call the brand’s customer service department at 1-800-462-8782; the campaign ID is N222362090.

It’s unclear how many Hummers have been delivered up to this point, so it’s hard to say if this program affects every single one on the road or just a percentage. Examples started , and GM reportedly . For comparison’s sake, Ford’s claimed production rate for the is more than 10 times better, at 150 a day. We’ve reached out to GM for comment, and will update this piece as soon as we learn more.