A Camshaft Position Actuator Control Circuit Low (Bank 1)
 

Hello everyone,
My name is Don and a little background on me, I was a motorcycle technician but now I am an instructor at MMI. I realize that my Audi is not a simple working on as motorcycles but I would think the general idea for a car engine is the same as a motorcycle engine :) Now to my issue.
I am having an issue and was wondering if I can get some input. I have tried searching thru the forums for this particular issue but have not found what I was looking for. I recently purchase a 2005 A4 cabriolet with the 1.8t. It does throw a code and the code is a P2088 A Camshaft Position Actuator Control Circuit Low (Bank 1). I have spent a couple weeks now trying to figure this out and can not find this code on any website or from a dealer as an Audi code. With that being said, I finally took it to an Audi dealer to troubleshoot it. I get a call back saying that its the "Camshaft adjustment unit" and they will fix it for the simple low price of $2400.00. It is my understanding that the part they are talking about is the cam chain tensioner for the variable valve timing, which seems like a fairly simple fix. The service manager at Audi will not verify for me that it is the same part that I am talking about. Has anyone had this issue in the past or know what they are talking about when they say "camshaft adjustment unit". And how does it work? such as the cam position sensor feeds a signal to the ecm and the ecm actuates the camshaft adjustment unit? Also can anyone tell me what voltage I should be getting out of the cam position sensor? If its anything like motorcycles it should be somewhere around a pulsing .5 to 5v.
Any help would be greatly appreciated, and I would like to thank you in advance for your help.

What you need is the VVT, according to your post here, the one for my 3.0 runs around 6-800 bucks (USD) depending on supplier, plus labor, the dealer does charge a lot. Also try scanning with a VAG-com tool, another audi/VW enthusiast around your area might have one that he/she can hook up to your car and run. Then you might realize that what you actually need is your cam sensor not your whole cam adjusting unit. Good luck! The cabriolet is a sexy car.

The camshaft adjuster unit for the 1.8 is #5 in this diagram. It's 058-109-088-K for 539.40 dollars and in stock from us. On the rear of the head (not pictured here) is the Cam position sensor 058-905-161-B for 109.37 but as you said that doesn't appear to be what you need by name or DTC.

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I would like to thank both of you for responding. I am towing it back home tomorrow and this weekend I will have to a look at it. What you have told me matches my thoughts, especially with the breakdown picture of it. Thank you again,
Don