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VWDoc, Independent VW Shop owner
Category: VW
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Experience:  20 years of experience working with VW's. Independent European shop owner and technician.
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My 2002 volkwagon passat has a trouble code of p0411 (Sec.

Resolved Question:

My 2002 volkwagon passat has a trouble code of p0411 (Sec. air inj. system incorrect flow detected) Is this something I can fix myself? Im not a mechanic but i do work on all of my vehicles myself.
Submitted: 7 years ago.
Category: VW
Expert:  marcpod replied 7 years ago.
I need more info like passat gls 4matic. Thanks
marcpod, Own collision repair advice
Category: VW
Satisfied Customers: 2881
Experience: i-car/Basf training, 300 repairs and 650,000 in Collision monthly 18 yrs exp/licensed adjuster
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Customer: replied 7 years ago.
passat 4 motion 1.8 turbo
Expert:  VWDoc replied 7 years ago.
Builder,
You'll need a handheld vacuum pump to start with. This will help eliminate a lot of unneccesary parts replacement.

Do you have such an item? Also, do you happen to have vag-com or other vw-specific scan tool?
Customer: replied 7 years ago.
Yes I have a hand held vacuum pump. What would I do with it?
Expert:  VWDoc replied 7 years ago.

Ok, the first thing I need to do is explain how the secondary air system works in your car.

 

When the engine is cold, emission levels are very high. The catalytic converter doesn't even begin to function until it reaches an internal temperature of over 400 degrees celcius. In order to get the cat up to operating temperature more quickly, your car has a system called the secondary air system. This system operates for about 2 minutes during a cold engine startup in order to pump oxygen into your exhaust stream, which in turn creates more heat in the exhaust, which gets the cat to operating temperature.

 

The system has the following components:

  • 40A maxi-fuse - supplies power to the pump and solenoid valve through the relay
  • relay - routes power to the pump
  • vacuum solenoid valve - opens to apply vacuum to the combi-valve
  • combi-valve - opens to allow pressurized air into the exhaust stream
  • pump - electric pump to pressurize air into the exhaust stream
  • vacuum hoses
  • pressure hose
  • intake hose

And that's about it.

 

Here is a diagram and legend under it

 

graphic

 

1-Combination valve

  • Checking, Refer to Air Injection Control Valve.

2-Gasket

  • Always replace

3-Bracket

  • Bolted at cylinder head

4-Gasket

  • Always replace

5-Bracket

  • Bolted at intake manifold

6-10 Nm
7-To recirculating valve for turbocharger -N249-
8-From vacuum - reservoir/intake manifold connection
9-6 Nm
10-Secondary Air Injection (AIR) solenoid valve -N112 */**

  • Resistance: 25 to 35 Q

11-Connector

  • 2-pin
  • green

12-O-ring

  • Replace if damaged

13-Pressure hose

  • Check for secure fitting
  • To disengage, squeeze together at front

14-8 Nm
15-Bracket

  • For Secondary Air Injection (AIR) pump motor

16-8 Nm
17-Secondary - Air Injection (AIR) pump motor -V101.**

  • Checking function, Refer to Air Injection Pump.

18-Connector

  • 2-pin
  • For Secondary Air Injection (AIR) pump motor

19-Intake hose

  • For Secondary Air Injection (AIR) pump

20-From air filter
21-Connection - tube
22-Elbow

  • Secure with screw type clamps or spring clamps

23-Pressure line
24-Connecting - piece

 

 

 

Now, I would bet that you have a vacuum leak at one of the lines either to or from the solenoid valve, which lives under your intake manifold near the throttle body. Check these lines carefully and let me know what you find.

VWDoc, Independent VW Shop owner
Category: VW
Satisfied Customers: 6457
Experience: 20 years of experience working with VW's. Independent European shop owner and technician.
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