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Dan, Technician
Category: VW
Satisfied Customers: 24209
Experience:  Independent Shop Experience, 2 Year Automotive Diploma, & Access to Information Database
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How do I resolve the error code p0411 in my 03 VW Jetta 1.8t

Customer Question

How do I resolve the error code p0411 in my 03 VW Jetta 1.8t
Submitted: 1 year ago.
Category: VW
Expert:  Dan replied 1 year ago.

Hello, my name is***** code is related to the secondary air injection system. The secondary air injection system pumps air via a blower motor into the exhaust to clean up exhaust emissions. This code means incorrect flow detected which usually is caused by a failed secondary air injection pump. The pump should come on during cold start, if your not hearing it then try to manually power the pump on. If pump still doesn't turn on it needs to be replaced. Let me know how it goes or if you have more questions, thanks.

Customer: replied 1 year ago.
My pump goes on during cold Start. So I don't think it's the pump. Can you tell me the series of checks I would go thru so I can check off the possibilities as I go thru them?
Expert:  Dan replied 1 year ago.

Check the Combination Valve (CV) for broken/loose vacuum or air supply hoses and repair as necessary. The CV is a one way check valve for the fresh air to be injected into the exhaust, is located on the cylinder head and has been described that it looks like an EGR valve. This vacuum line is common to crack which can cause this problem. If everything looks good use a vacuum pump to see if you can open valve, if not replace. Let me know how it goes or if you have more questions. Thanks.