The secondary air valve isn't responding.
P0413 — also written PO413, P 0413, 0413 — is the OBD-II code for secondary air injection switching valve a — open circuit. Same code, same fix: this page covers every spelling of it.
This code means the electrical circuit to the air switching valve is broken, usually seen on older VW Golfs or Mercedes where the solenoid coil has finally burnt out.
P0413 is a emissions fault code, typically costing £120–£500 to put right in a UK garage.
What P0413 actually feels like to drive
- The engine light pops on specifically during the first 60 seconds of a cold start.
- A loud 'hairdryer' noise from the engine bay that stops after a minute.
- A slight hesitation or 'stumble' just as you pull out of the driveway on a frosty morning.
- No difference in performance once the car is up to temperature.
- Failure on the 'Visual Inspection' part of the MOT if the EML is glowing on the dash.
What causes P0413?
- Failed valve
- Wiring fault
- Broken vacuum line
UK vehicles that throw P0413 most often
- VW Golf Mk4/Mk5 1.6 & 2.0 (1998-2008)
- Mercedes-Benz C-Class (W203/W204) C180/C200 Kompressor
- Audi A3 1.8T (BAM/AUQ engines) 2000-2005
- Vauxhall Astra G 1.6 16v (Z16XE) 2000-2005
- Mini Cooper R50/R53 2001-2006
How P0413 is fixed
- Replace switching valve
- Repair wiring
The P0413 misdiagnosis that wastes money
I see too many lads jump straight to swapping the actual air pump because it’s the 'big' part, but that's a £400 mistake. Nine times out of ten, the pump is fine; it's the little solenoid valve that's given up the ghost or a tiny bit of vacuum hose that's perished and snapped. People also get confused and start cleaning EGR valves, thinking it's the same system. It isn't. P0413 is strictly an electrical 'open circuit'—the car's brain can't see the solenoid at all, usually because the internal coil has snapped or the plug is green with corrosion.
What a UK garage should charge for P0413
For a basic diagnostic plug-in, you’re looking at £50-£80 at an indie. A genuine Pierburg or Bosch switching valve will set you back between £45 and £110 depending on the car. Labour is usually an hour—roughly £70 in my neck of the woods. If you go to a main dealer, expect that to double. Total bill usually lands around £180 for most common cars, though some Mercs can push towards £400 if the valve is a pig to get to.
P0413 repair cost in the UK
Most P0413 repairs land between £120–£500 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 P0413
Before you let a garage sell you a pump or a valve, ask them to do a simple 'active test' with their scan tool. If they can trigger the solenoid and you hear a 'click', the circuit is fine and it's a mechanical blockage. If it doesn't click, tell them to check the pins for 12v power first. These valves are often tucked right at the back of the block on VAG engines; I’ve seen many where the wiring loom has rubbed raw against the heat shield. Don't pay for a new part until they've verified the wire isn't just snapped.
Can you drive with P0413?
Yes.
Urgency: low.