Does electronic rust protection actually work on cars?

No. Independent salt-spray chamber testing shows vehicles with electronic modules rust at roughly the same rate as unprotected vehicles. The technology relies on a continuous electrolyte (a conductive liquid) covering the metal to complete the cathodic protection circuit, the way seawater does on a ship. A car on rubber tires with mostly dry metal does not provide that conductor, so the small current cannot reach the hidden seams and cavities where rust actually starts.

Why does cathodic protection work on ships but not on cars?

Cathodic protection requires the protected metal to be submerged in a continuous electrolyte. On a ship, that is seawater. On a buried pipeline, that is moist soil. On a car, the body sits in air, the tires insulate it from ground, and the hidden cavities where rust starts are dry pockets disconnected from any conductor. The science is real for the right environment. A car is not the right environment.

Have courts or regulators ruled on electronic rust protection devices?

Yes. The Federal Trade Commission in the US has ordered companies selling automotive cathodic protection devices to stop and pay restitution for unsupported claims. The Competition Bureau of Canada has investigated multiple companies and forced products off the market for the same reason. Corrosion control professionals and Wikipedia's page on cathodic protection both note that automotive devices have no peer-reviewed scientific support.

How much do dealerships charge for electronic rust protection?

Most dealerships sell the modules for 500 to 1,200 dollars as a one-time add-on on a new vehicle. The markup is high and the devices are simple, which is why they are pushed at the finance and insurance desk. By comparison, an annual Rust Check application starts at 140 dollars and is designed to actually reach the hidden cavities where rust begins.

Will an electronic rust module drain my battery?

The draw is small but constant. The device pulls a trickle of current from your battery 24 hours a day. For a daily driver, the alternator keeps up. For a vehicle that sits for extended periods, the constant draw can contribute to a dead battery. It is not the main reason to skip the device, but it is a real factor.

I already paid for an electronic rust module on my new car. What should I do?

Start annual oil-based rust protection now. The module does not interfere with a Rust Check application, so you can leave it installed if you want, the LED light will keep blinking either way. The important step is getting actual protection into the body cavities and onto the undercarriage before another Ontario winter goes by. The earlier you start, the more accumulated coverage you build year over year.

Does the dealership warranty on the electronic module require regular re-checks?

Some dealership rust warranties tied to electronic modules require annual inspections at the selling dealer to stay valid. Read the paperwork carefully. The warranty itself often has narrow exclusions that make claims difficult, which is part of why these products have drawn regulatory attention. An aftermarket oil-based annual treatment cannot void your factory rust-through warranty in Canada.

Will Rust Check work on a car that already has an electronic rust module?

Yes. The two products do not interact. Rust Check is a physical oil-based treatment that displaces moisture and coats metal in seams, cavities, and the undercarriage. The electronic module is wired to the battery and operates independently. We apply Rust Check the same way regardless of whether a module is present.

Rust Check vs Electronic Rust Protection: A Showdown

Dealerships sell electronic rust modules for hundreds of dollars. Courts in Canada and the US ordered companies to stop. Here's why oil-based protection wins.