Dear U.S. Diver,

Hope you're well and stay so. I cannot respond to your first question as to the best source for a re-manufactured ECU. As the factory-original units seem quite durable, I'd prefer to have two or three "used, known-good" units (factory-original), rather than a single re-manufactured unit.

Dave Stevens has wisely pointed out that a re-manufactured unit could have had only obvious failures remedied; other parts might be inobviously damaged. A 25-year-old factory-original unit could still have considerable life left in it.

Heat and humidity (moisture) are enemies of electronics. In sourcing used engine or ignition control modules, I'd look where lower - rather than higher - average ambient temperatures prevail. So, a unit from a car that lived in Nebraska or North Dakota would be preferred to a module from a car that lived in from Arizona or Florida.

On a 940, to ascertain the part number of the in-service engine control unit, you'll need to remove the plastic passenger-side foot-well panel (door-side). The ECU is held in a frame. You'll need to remove the ECU from the frame, but NOT disconnect it from the wiring harness. If I recall correctly, two or three T-20 screws need to be removed, to take the frame free.

For most normally-aspirated (non-turbo) 940s sold in North America, with the FD (non-turbo) engine, the Bosch Part number marked on the ECU is: 0 280 000 946. Some of the later '95 940s bear number 0 280 000 943.

I hope these comments are helpful.

Yours faithfully,

Spook