Most common cause is a weak 12V battery — EPBs need a minimum voltage to operate, and a battery dropping below about 11.5V will refuse to release. Second most common: a seized actuator motor on the rear caliper, typically after winter salt corrosion. Third: a software glitch that needs a dealer-level reset.
Electric handbrakes have made cars cleaner inside but they've created a whole new category of "won't move off the drive" jobs.
Can I fit a new battery myself if that's the cause? — On stop-start cars, the new battery has to be 'coded' to the BMS — otherwise the alternator overcharges it and you'll be back in 6 months. Most independents charge £25-£40 to register a new battery.
Why does the EPB always fail in winter? — Salt water + tiny exposed motor + freezing temperatures = corrosion. The motors aren't sealed brilliantly. A regular underbody wash through winter genuinely helps EPB life.
Is an electric handbrake worse than a cable one? — More to go wrong, more expensive when it does, but the parking brake itself usually holds the car better. The trade-off is dealer-level diagnostics for nearly any fault.
Bob's Mechanical Repairs — independent family-run garage in Birnam, Dunkeld, Perthshire. Call 01350 727 276 or email [email protected].