I keep seeing references to "EEC" (electronic engine control) and "PCM" (powertrain control module) in my Ford manuls. I'm somewhat confused (not surprising). Are these two seperate devices? Are they actually one in the same? Whatever the case may be, where is (are) it located in my 93 F250. Any help to unconfuse me is appreciated.

 

if you look on your driver side under the brake booster lower right side you will see it close to the fender held in buy 2 10mm nuts and a black weather strip and if you un-bolt you e-brake and pull it off to the side you will be able to get a good look at it .the e-brake is easer to remove if you want or you will need to loosen the fender well to remove the pcm.

 

EFI computers are called many names by different manufacturers. Ford calls them EEC and has since the mid 80's. GM used to call them ECM's, then eventually PCM's when they changed technology.

You'll find that ECM, EEC, PCM are used fairly interchangably, and in most cases mean the same thing.

 

Ford has had three different computers and their main job was different. All three overlapped in years.

First came the ECM (Electronic Control Module) in about 1978 early units was mostly on California Trucks at first but were used on other trucks in the early 80’s and their main job was pollution control.

Then with EFI Ford came out with the EEC (Electronic Engine Control) this one did two main jobs, engine control and pollution so they had to change the name. It gave a two number fault codes.

Then they added the Transmission to the batch so the name had to be changed again to PCM (Powertrain Control Module). Now it did three main jobs and could not be covered by a two-digit code so the PCM has a three-digit code.

Some years in the late 80’s and early 90's they used both the EEC and PCM but after that they used the PCM on all of them.

 

Thanks for the quick and wise responses to my question re EEC/PCM. I guess the manuals from Ford use both terms because not all instances of the phrases throughout the manuals are updated form year to year.