# 17887 - Brake Boost Vacuum System: Mechanical Failure



## fritzner (Aug 3, 2001)

i just got these 2 codes on my '02 A4 1.8T..
17887 - Brake Boost Vacuum System: Mechanical Failure
P1479 - 008 - Implausible Signal
16795 - Secondary Air Injection System: Incorrect Flow Detected
P0411 - 002 - Lower Limit Exceeded
i have found some posts on 16795 (SAI), but nothing on the 17887.. 
any ideas what 17887 means??.. the brakes work fine.. is it safe to drive the car??.. where is the brake boost vacuum line on a longitudinal 1.8T (A4)??..
any help would be greatly appreciated..
thanks ..


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## fritzner (Aug 3, 2001)

*Re: 17887 - Brake Boost Vacuum System: Mechanical Failure (fritzner)*

i was told the 2 codes are both caused by a vacuum leak..
i am pretty sure i fixed it.. the vac line on the combi valve was completely deteriorated.. i replaced it and cleared the codes.. it usually took a day or 2 for the codes to come back, but i would bet that will fix it..
BTW: 
the combi valve on my A4 is near the center close to the firewall..
thanks for your help..


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