Fault codeP0413

MODERATE

Secondary Air Injection System Switching Valve A Circuit Open

What this code means

Secondary Air Injection System Switching Valve A Circuit Open.

P0413 is a generic code: it means the same thing on every make. P0413 belongs to family P04xx — Emission controls. Its page explains how to read a code and groups all its codes by part.

Type of fault

The control unit no longer sees continuity in this control circuit: a broken wire, an unplugged connector, or an open winding in the component. A multimeter checks both the component's resistance and the continuity of the wires.

Secondary air injection

On some petrol engines, an electric pump blows fresh air into the exhaust for the first minute after a cold start. The extra oxygen helps the catalytic converter reach its working temperature faster. A valve opens the air path and prevents exhaust gas from flowing back.

What you notice

Usually nothing in driving; sometimes a pump noise that stays or is missing at cold start, and a failed emissions test.

How to check it

The pump and the check valve often suffer from moisture: condensation corrodes the pump, and a leaking valve lets exhaust into the system. Check the relay, the fuse, the hoses and the pump's operation at cold start: it should be heard running for about a minute.

Watch it live in Klaro

With an OBD2 adapter plugged in, these live readings show the part at work, when your car reports them:

Short term fuel trim bank 1
Long term fuel trim bank 1

What to do

Have it checked this week. The car remains usable, but the fault will not clear itself and will fail the roadworthiness test.

Clearing a code switches the light off but repairs nothing: if the fault remains, the code comes back. Clearing a fault code yourself →

How to read this code

PPowertrain
0standardised code
4Emission controls
13P0413