Need help Please-Knock sensor control unit

My friend has a 1986 Golf/ GTI and the mechanics are telling him that the knock sensor control unit is bad and is keeping the car from starting. Can anyone tell me if this could be legit and is there anyway to bypass it to see if it is the problem? I am in the Air Force and stationed on an Island so getting good solid info is hard and I am not really familiar with these cars, but I couldn't sit and watch my friend change a bunch of wiring and spend a bunch of money when it didn't seem to be right. I do have pictures of the part and can send them if needed. Can anyone help? A part # and source would help too. Thank you.
CWL

The knock sensor is wired straight to the engine computer, I don't know of a knock sensor control unit. I take it that you have no spark. The best first step is to pull the 3-wire distributor harness & turn on the ignition & check for 12V between the outer two wires. If that's good then re-plug the connector & backprobe the center wire with a LED test light hooked to battery positive & crank the engine. The light should flash or the Hall sensor in the distributor is bad.

The knock sensor is wired straight to the engine computer, I don't know of a knock sensor control unit. I take it that you have no spark. The best first step is to pull the 3-wire distributor harness & turn on the ignition & check for 12V between the outer two wires. If that's good then re-plug the connector & backprobe the center wire with a LED test light hooked to battery positive & crank the engine. The light should flash or the Hall sensor in the distributor is bad.
Hey thanks I'll give it a try! I do have pictures of this control unit, if you would like to see what it looks like let me know and I'll send them to ya . Thanks again