99 LeSabre? Mystery Part.

In my '96 Bonneville with the 3800 Series II, it is the Powertrain Control Module (PCM).

We have a 98. Have never noticed this, but will go outside and see if I can see what you're talking about.

Boy that's a great spot to put the PCM in the front fender. Its the second thing to get crushed when you smash the fender.

Plus from the heat warp the outer black cover tabs no longer contact the lower portion of the box with the mating tabs.

Harryface

It is in fact the PCM.

Mine is the same way. As for the box, I noticed it in my car when I first got it and thought (like you did) that it was part of the car's aftermarket alarm system. It took 2 months for me to stumble on a site which told me what it was. Weird, very weird. You gotta wonder who designs these things.

Its the computer. GM started putting them in the engine compartment in the early '90s. I bet the engineer that thought that one up is real proud of himself.

The Computer board will Warp / Melt causing soldering joints to expand and the board to crack and componant damage. Im surprised by hearing this. I wonder how many years GM did this ??? Brian - Las Vegas

They still do.

DS

So far I don't see no computer under the hood of the Park Ave. Behind the glove box in the Bonneville.

Harryface