Fault code P0414 – a step-by-step guide to diagnosing and fixing it

The meaning of error code P0414 – Secondary Air Injection System Switching Valve A Circuit Shorted

P0414: Causes, signs and repairs

Error code P0414 is displayed and the check engine light is on - what does this mean?

The OBD-II system has detected a fault in the secondary air system, more specifically a malfunction of the secondary air injection bank 1. This DTC P0414 indicates that the control unit has detected an unexpected voltage value or a faulty function of the secondary air pump or its circuit.

What can cause this error code?

Defective secondary air pump
Damaged or blocked secondary air valve
Defective secondary air injection relay
Broken or damaged cable connections
Blocked secondary air lines or hoses
Faulty fuses in the secondary air system
Defective engine control unit (ECM)
Corroded plug connections

What symptoms occur in parallel with fault code P0414?

Increased emission values: The vehicle exceeds the permissible exhaust emission limits
Poor cold start performance: Extended warm-up phase and rough engine running
Check engine light: Permanent illumination of the check engine light
Failed emissions test: Problems with the HU/AU due to increased pollutant values
Irregular idling: Fluctuating engine speed, especially when the engine is cold

How can the problem with error code P0414 be rectified?

The repair requires a systematic diagnosis of the secondary air injection in order to identify the exact source of the fault.
Checking and replacing the secondary air pump including relay and fuses
Cleaning or replacement of the secondary air valve and all associated vacuum lines
Complete inspection and repair of the wiring between the ECM and secondary air system
Replacement of blocked or damaged secondary air hoses and lines
Professional diagnostics with OBD scanner to check the system function after the repair

FAQ - Frequently asked questions about DTC P0414

Can I continue driving with error code P0414?

Yes, the vehicle can still be driven, but you should have the fault rectified as soon as possible. The secondary air system is important for emission control, and a defective system can lead to increased pollutant levels and a failed emissions test.

How much does it cost to repair error code P0414?

The repair costs vary between 150-800 euros, depending on the cause. A defective secondary air valve costs around 150-300 euros, while a new secondary air pump can cost 400-800 euros. The diagnosis costs 80-120 euros.

How do I recognize a defective secondary air pump on P0414?

A defective secondary air pump often makes unusual noises when starting cold or does not start at all. You can also check whether the pump is receiving power and whether the vacuum lines are intact.

Can I repair fault code P0414 myself?

You can carry out simple repairs such as checking fuses, relays or vacuum hoses yourself. However, replacing the secondary air pump requires automotive expertise and should be left to a workshop.

How long does it take to repair P0414?

Depending on the cause, the repair takes 1-4 hours. A simple valve cleaning can be completed in an hour, while replacing the secondary air pump can take up to 4 hours.

Does the error code P0414 return after the repair?

If the repair has been carried out correctly, the code should not return. If it does, there may be an additional defect or the repair was incomplete. A new diagnosis is then required.

Vehicles in which fault code P0414 occurs most frequently

Error code P0414 is a cross-manufacturer EOBD code that indicates problems with the secondary air injection and can occur in various vehicle brands, but is most common in the following vehicles:

BMW: 3 Series E46, 5 Series E39, X5 E53 (1998-2006)
Mercedes-Benz: C-Class W203, E-Class W211, S-Class W220 (2000-2009)
Audi: A4 B6/B7, A6 C5/C6, A8 D2/D3 (1999-2008)
Volkswagen: Golf IV/V, Passat B5/B6, Touareg (2000-2010)
Ford: Focus, Mondeo, Explorer (2001-2008)
GM/Opel: Vectra C, Astra H, Zafira B (2002-2010)
Toyota: Camry, RAV4, Highlander (2001-2009)
Nissan: Altima, Maxima, Pathfinder (2002-2008)

If code P0414 occurs in your vehicle, you should first have the secondary air pump and the associated components checked. As this fault code affects the emission control system, it is important to have it repaired promptly in order to comply with environmental regulations and pass the next main inspection. A professional OBD diagnosis helps to identify the exact cause and avoid unnecessary repair costs.

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