Finding & Replacing Your Saab 9-5 Engine Control Unit
In the 9-5 the Engine Control Unit is located underneath the false bulkhead (plastic panel) that sits between the windshield and the engine compartment.
To remove it you'll do the following:
Remove the small plastic Philips screw on the far right side of the bulk head (will be left side standing outside of car looking into the engine area)
Remove the right side windshield wiper (NOTE: Some people choose not to do this. I personally don't myself. It does allow lots of extra room however to see and move around)
Lift up on the bottom edge of the plastic panel, while sliding the top edge down to move it out of the way. I personally just pull the side up and stuff a rag to keep it elevated. Just don't lift it so high that you break it.
The ECU is covered by a rubber boot. Remove the (4) 10mm nuts that hold it down.
Once the cover is removed you will undo the harness connector by swinging the arm up, and then lifting the whole wiring bundle straight up.
The final removal can be done by removing the (2) 10mm nuts that hold the unit to the chassis. There is one on each side.