P2440 Generic (SAE) Basic entry

Secondary Air Injection System Switching Valve Stuck Open

Updated 2026-10-02 · Fuel, air & emissions (P2)

Severity

Medium

Typical repair cost

80 – 600 EUR

System

Powertrain

What it means

P2440 is stored when the engine control module commands the Secondary Air Injection System Switching Valve to move but the feedback shows it stays in one position. The cause is mechanical binding, carbon or dirt, or a failed actuator.

This entry is compiled automatically from the standard definition and typical diagnostic practice for this type of fault. A detailed, reviewed article is in preparation.

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Symptoms

Check engine light on
Rough or unstable idle
Hesitation or poor acceleration
Increased fuel consumption
Possible limp mode with reduced power

Common causes

Carbon, varnish or dirt build-up blocking movement
Worn or seized actuator mechanism
Broken return spring or linkage
Failed position feedback sensor giving a false reading
Low supply voltage to the actuator motor

How to diagnose

Command the Secondary Air Injection System Switching Valve with a scan tool and watch the feedback position
Remove and inspect the component for carbon, dirt or mechanical damage
Clean the mechanism and check it moves freely through its full range
Measure supply voltage and resistance of the actuator motor
Replace the actuator if it still does not follow commands

Frequently asked questions

Can I keep driving with P2440?

Usually yes for a short time, but expect reduced performance or higher fuel use. Have it diagnosed within a few days.

Will clearing P2440 fix it?

No. Clearing only erases the stored code; it returns as soon as the monitor runs again unless the cause is repaired.