Replacing ECM in '89

[Padgett]

Because the 91 L27 changed the whole oil filter mount.

[Ronnie]

@89 MAUI Did you ever get your problem resolved? Can't help but wonder what it took to fix it.

[Padgett]

Help desk syndrome: when the user stops calling it is fixed.

[Nailhed66]

I look forward to the day I can report here that my ‘ 88 is fixed. I’ve had to push it onto the back burner due to an overload of other projects. ✌️

[Barney Eaton]

The oil pressure sending unit screws into the oil filter adaptor and Buick used 3 different oil filter adaptors between 1988 and 1991 so the oil pressure sending unit might be horizontal or vertical depending on the adaptor. 

The ECM never just slides out,  you have to get totally pissed then it come out....... however if you think you need a new one,  just unplug the old one, plug in the new one and lay it on the floor and take the car for a test drive. 

then if you really need to change it pull the glove box, screws, and hope it come out easily. 

[Padgett]

BTW the 88-90 (C engine) oil pressure sender is calibrated differently than the 91 (L engine). They fail so often I always kept a spare on hand.

 

For the ECM, peeling back the carpet and underlay helps.

Edited August 24, 2021 by Padgett