Brake light switch circuit fault.
P0571 — also written PO571, P 0571, 0571 — is the OBD-II code for brake switch 'a' circuit. Same code, same fix: this page covers every spelling of it.
P0571 means your car's brain is confused about whether your foot is on the brake pedal or not, usually because the two-way switch behind the pedal has bit the dust. It's a classic on older VWs and Fords where the cruise control suddenly gives up the ghost.
P0571 is a electrical fault code, typically costing £30–£150 to put right in a UK garage.
What P0571 actually feels like to drive
- Cruise control flat-out refuses to engage on the motorway.
- The 'ESP' or Traction Control warning light stays on the dash.
- Brake lights are either stuck on permanently or won't light up at all.
- Automatic gearbox won't let you shift out of 'Park' without a fight.
- Engine feels like it's 'cutting out' or hesitant when you're just cruising.
What causes P0571?
- Failed brake switch
- Wiring
- Brake pedal misalignment
UK vehicles that throw P0571 most often
- Volkswagen Golf Mk5/Mk6 (1K/5K) 2004-2013
- Ford Focus Mk2/Mk3 1.6 TDCi 2005-2015
- Vauxhall Astra J (A14NET/A17DTE) 2009-2015
- Land Rover Discovery 3/4 (TDV6) 2004-2016
- Nissan Qashqai J10 1.5 dCi 2007-2013
- Audi A3 (8P) 2.0 TDI 2003-2012
How P0571 is fixed
- Brake switch replacement
The P0571 misdiagnosis that wastes money
I’ve lost count of how many times customers have come in after fitting a £10 eBay switch themselves, only to find the fault’s still there or their cruise control is still dead. They assume because the brake lights work, the switch is fine. It’s not. Most of these modern UK wagons use a four-pin 'hall effect' or dual-contact switch—one circuit for the bulbs, one for the ECU. We often find the actual fault is a blown fuse caused by a short in the tow-bar electrics or a corroded rear light cluster on a Transit, yet people keep lobbing switches at it.
What a UK garage should charge for P0571
For a standard Bosch or Febi Bilstein switch, you’re looking at £15 to £40 for the part. At an indie garage like mine, we’d charge about 0.5 to 1 hour of labour, so £60 to £100 all-in. If you go to a main dealer, expect to get stung for a £120 diagnostic fee before they even touch a spanner, plus they’ll charge you double for the 'genuine' boxed part. The whole job shouldn't top £150 unless there's a nightmare wiring break in the loom.
P0571 repair cost in the UK
Most P0571 repairs land between £30–£150 including parts and labour. The spread is wide because the cheap fix (a sensor, a hose, a leak) and the expensive fix (a major component) throw the same code — which is why a proper diagnosis before parts are bought saves the most money.
Bob's tip on P0571
Before you let a garage swap the switch, ask them if they’ve checked the 'live data' on their scan tool. A decent independent should be able to show you the ECU seeing the pedal as 'Pressed' or 'Released' in real-time. If you've got an Astra or a Corsa, check your rear bulbs first; if you've fitted a cheap non-branded single-filament bulb where a double-filament should be, it can back-feed the circuit and pop this code. Don’t pay for a diagnostic if it’s just a 50p bulb you’ve put in backwards!
Can you drive with P0571?
Brake lights may not work — get fixed urgently.
Urgency: medium.