Ryuu1994

Hello,

I recently purchased a 2003 Audi A4 3.0 Avant and immediately after it started having issues. It currently has 158,000 miles on it. I'm debating if I should keep this car or if I should get something else. I would like some advice what others have experienced with their vehicles. I recently took it to a mechanic and they mentioned that replacing the spark plugs and ignition coil will take care of the flashing check engine light. The codes that were stored on the engine module are:

18080 - fan control circuit - sporadic
16688 - cylinder 4 misfire
18010 - power supply terminal 30 too low
18032 - malfunction lamp on active - implausible signal (transmission code)
Passenger door has stopped locking as well.

Thank you so much for your time, it's appreciated!

turbo510

We really can't tell you to keep it, or to get something else. However, lots of 20 year-old cars have things wear out or need maintenance. Regarding the codes, cylinder misfire may indeed be a failing coil. The coils are NOT particularly expensive, so if that #4 coil was being replaced, doing the entire set might be a good idea. If you can do this job yourself, a set of 6 new plugs and coils is $210 at autohausaz.com. Misfire can be due to other things though, such as oil soaking the spark plug from above due to an old valve cover gasket, or a dirty fuel injector, or electrical connections.

The fan control circuit might allow the engine to overheat in stop-and-go traffic during summer weather. Some years ago my fan module was replaced.
Power supply terminal 30 fault could be an old fault code, due to attempting to start using a weak battery.
CEL due to transmission code: You would need to have the transmission's control unit scanned to know what that's about. Many Audi owner's have a VCDS scan tool which will do that, also about $200.
Passenger door lock: Can be the small motor in the latch assembly not running. We had a Q5 with that problem; I was able to clean the motor's commutator, but it was not a quick job.

JasoninBRLA

I also have a 2003 and just replaced the fan control module. Not very expensive. After I changed it out, I determined it wasn't the module but the fans weren't running at full speed like they should be.

So I took the front off, and changed out the fans which were about $150. While I was there I replaced timing belt, thermastat, water pump, etc. Now it runs great and ready for another 220,000 miles.

What I am saying, is its a 20 year old car. Stuff is going to break. The good thing is these cars are pretty easy to work on and aftermarket parts are readily available and cheap.