If you have the mechanical ability and tools, here is a post by GotEngines.com on DIS and some diagnostic tips. Other wise go to a competent repair shop with qualified mechanics.

Distributor less ignition systems (DIS) have been around for almost a decade now, and have eliminated much of the maintenance that used to be associated with the ignition system. No distributor means there’s no distributor cap or rotor to replace, and no troublesome vacuum or mechanical advance mechanisms to cause timing problems. Consequently, DIS ignition systems are pretty reliable.

Even so, that doesn’t mean they are trouble-free. Failures can and do occur for a variety of reasons. So knowing how to identify and diagnose common DIS problems can save you a lot of guesswork the next time you encounter an engine that cranks but refuses to start, or one that runs but is missing or misfiring on one or more cylinders.

If an engine cranks but won’t start, is it fuel, ignition or compression? Ignition is usually the easiest of the three to check because on most engines, all you have to do is pull off a plug wire and check for spark when the engine is cranked. On coil-over-plug DIS systems, there are no plug wires so you have to remove a coil and use a plug wire or adapter to check for a spark.

If there’s no spark in one cylinder, try another. No spark in any cylinder would most likely indicate a failed DIS module or crankshaft position sensor. Many engines that are equipped with electronic fuel injection also use the crankshaft position sensor signal to trigger the fuel injectors. So, if there’s no spark and no injector activity, the problem is likely in the crank position sensor. No spark in only one cylinder or two cylinders that share a coil would tell you a coil has probably failed.

Testing your DIS requires at least a hand help scan tool. Using this affordable tool will tell you what and where the problem is. It won’t tell you how to fix it or give any repair data. To get repair data and more you need a professional scanner, which costs over three thousand bucks

This is about as baisc description on DIS GotEngines.com Blog can come up with. My advise to most people would be to let a professional work with it. It may cost more if you try first.