My brother purchased a new car and donated his 2002 Audi A4 Quatro 1.8 turbo to me. Car runs great, but check engine light is on. Dealer says:

"Inspected and found electrical malfunction fault for camshaft adjuster. Performed output test for adjuster and it failed. Adjuster is faulty, replacement recommended. $1994.68"

I verified using an inexpensive code scanner which showed codes

16396: specification not reached for adjustment to advance camshaft
17937: camshaft adjustment short circuit to battery voltage

I am guessing that the computer is reading the first code from the camshaft position sensor, and the second code is the result of getting an incorrect voltage or resistance back from the solenoid when an adjustment signal is sent to it.

Bought a Haynes manual to check out the repair, and the manual is rather sparse on that particular repair, but it is obviously more than I can handle. Read somewhere that just the adjuster "solenoid" can be replaced by itself without taking out the entire adjuster. It appears the solenoid sits on the outside of the adjuster where it can be accessed without a lot of disassembly of the head, and although it apparently is not available for purchase separately from the adjuster, I would certainly consider the price of the whole adjuster unit to get the solenoid, if that could fix the problem. Anyone else have any experience with this issue?

 

How many miles on the car? It may be wise to replace the whole tensioner. Just did mine about 3 weeks ago and the bottom chain guide (hard plastic) was missing/broken. Had to drop the oil pan to get all the chunks out. Could cause the oil pick up tube to clog up and then you'd be in real trouble starving the motor of oil.