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P0411 VW/Audi Engine Code: Secondary Air Injection System – Insufficient Flow Detected
When a P0411 fault code for your VW pops up on your OBD scanner, it leads you directly to the secondary air injection system because it will read “Secondary Air Injection System – Insufficient Flow Detected “ but can cause confusion pinpointing the exact issue. As the definition states, the ECM has detected nonoptimal flow in the secondary air injection system. Within this post, you will find information on how to diagnose and repair the engine code P0411. It has been said that this code is most common in the 2.5 engines. Also, you will not pass an emissions test if your vehicle is reading the P0411 code.
Applications this affects:
- VW Jetta
- VW Golf/GTI
- VW Beetle
- VW Eos
- VW CC
- VW Passat
- VW Rabbit
- Audi A4
- Audi A3
- Audi S4
What is the Secondary Air Injection (SAI) system and what does it do? Essentially, the secondary air injection system’s main purpose is to inject air into the exhaust to lower emissions. When the secondary air injection system pumps extra air into the exhaust on a cold start, it serves two functions: it breaks down unburned fuel and it heats the catalytic converter at a quicker rate to reach your engine’s optimal levels.
The secondary air injection system is made up of many components: secondary air pump, secondary pressure sensor, combination (Kombi) valve, a control relay, and numerous hoses/pipes connecting the components.
The tough thing about a P0411 code is, most of the time, no other symptoms will be present except for the Check Engine Light illuminating. What symptoms can you look for when you get a P0411 engine code?
P0411 VW Symptoms
- Check Engine Light (CEL) Illuminating
- Secondary air pump making a whishing sound
- Engine backfiring
- Slight engine hesitation
Causes of P0411 Fault Code for Volkswagen
- Secondary air pump failure
- J299 Relay burnout
- Combination (Kombi) valve failure or carbon buildup
- Secondary air pressure sensor failure
- Secondary air hose leak or carbon buildup
- Bad Mass Air Flow (MAF) Sensor – Rare
How to Diagnose a Volkswagen with a P0411 Engine Code
It is hard to diagnose exactly what is wrong with the secondary air system when you get a P0411 code, but we’ll give you steps to lead you in the right direction to repair your vehicle.
- Plug in an OBD Scanner to confirm that you have a P0411 code
- Visually inspect the J299 relay associated with the secondary air injection system in the ECM housing and make sure it isn’t blown
- Visually inspect the secondary air pump
- Visually inspect the hoses/pipes attached to the air pump
- Visually inspect the Combination valve
- Visually inspect the secondary air injection solenoid valve (N112)
- Visually inspect the secondary air pressure sensor
The location for all of the parts listed above are in similar places for different engines, but here is a few pictures to help:
2009 – 2017 CC | 2008 – 2010 Volkswagen Passat | MK6 Jetta | MK6 GTI
MK7 GTI & MK7 Golf
Credit to ModdedEuros.com
How to Repair a Volkswagen with a P0411 Engine Code
The three most common causes for a P0411 fault code are burnt-out J299 relay, leaking secondary air pump, or combination valve failure. Since they are so many Volkswagen engines that have secondary air injection systems, we are going to do the 2.5’s since this failure does happen to occur on these engines the most. If you need more information on what parts you need for your specific engine, leave a comment below and we’ll make sure to get back to you as soon as possible.
Replacing the J299 Relay for a Volkswagen
2.5L Secondary Air Injection System Relay Location:
2.5L Relay Replacement
Replacing the Secondary Air Injection Pump for a Volkswagen
One way to test if your air pump is the reason for the P0411 code is to cold-start your vehicle and listen to the air pump to see if it is running. It should be running for 90 seconds after a cold start to inject extra air into the exhaust. If it is not, first check the J299 relay and if it isn’t burnt, then you will want to replace the pump. Another way to test a faulty air pump is to listen to hear if air is leaking out of the pump itself. If either of these is occurring, you will want to replace the secondary air injection pump itself.
Order Here: VW 2.5L OEM Secondary Air Injection Pump Replacement
DIY Difficulty: Intermediate
*The above video is for a vw 1.8t but should point you in the right direction on how to perform this DIY
Replacing the Combination (Kombi) Valve for a Volkswagen
If the combination valve is stuck on open, you will need to fix this or take it into a shop ASAP. If this goes on for too long, moisture will invade the secondary air pump and ruin that part as well.
DIY Difficulty: Difficult
To sum it up, a P0411 engine code for your Volkswagen is something that needs to be fixed ASAP if you are in an emission-sensitive state or province as it will not pass the emissions test. We did only do the 2.5 Volkswagen engine because there are so many other engines this problem can apply to, so if you need assistance in figuring out replacement parts, diagnosis, or location of parts in another engine, please drop a comment and we’ll make sure to help you out.