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Locating ECM

i am trying to locate the ECM on my car, i have been looking and have asked several people, and everyone has said another location and i have checked them all

What year Ciera?

What year is your car? You may not have one.

it is an 84’ and it does have an ECM

It either behind the glove box or in the passenger side kick panel, the panel between the fire wall and the door under the dash board.

that is waht i have been told as well as under thecarpet on the floor board, i know what it looks like but can’t seem to locate… maybe i need to look again, and open my eyes…lol , thanks for the help

It is a simple aluminum box with two large wire connectors on one side and a plate cover held with a single screw for access to the PROM chip. It may be in a black plastic sleeve. IIRC, a single bolt holds it in place. You can’t miss the big wire harness running to it.

A nice place to put it would be just above the passenger’s right foot where the floor becomes the firewall. Computer–firewall? Sounds kind of familiar. It was located there in a 1985 Cadillac but it could be in the ashtray for all I know. There are Haynes manuals everywhere with computer locations in them.