I have a 94 blazer. Jet says it's under the glove box. There isa huge electronics center there that runs from the speaker to the bottom (knee boster). I thought the white piggy- back case was the ECM module- but it is a circuit board- probably for ABS. I disconnected the 5 connectors and that sucker will not come out the bottom! I have the lower dash out and pulled the main dash out 2" and no go.The next step is a big commitment- this is no easy dash to pull. I read on WIKI the ECM is under the distributor cap- that would be nice. Deer season is upon us- WHO KNOWS IF I NEED TO PULL THIS SUCKER???

 

I havea reply for us all. The electonics module under the glove box is a sandwich of2 modules tied together withsheet metal and 2 nuts and a piggy back module that can stay put. I had to separate the sandwichtolower the assemblyfrom the tight fitin the upper dash. The larger case is the ECM module, and it has the accesss panel indicated in JET's instructions. The 60 (approx)double in- line pin connecter has to be centered in the OEM connnector- this leaves 2 pins vacant on each side- thanks for not telling me that! I'm very happy with the performance from the JET stage 1- I don't know the mileage yet. Just thought everyone should know...