Removing the ECU (archive)

The ECU on my car ('86 535i, US model) is above the glovebox. I never replaced the chip, but here's what I remember about removing the ECU:
-Disconnect the battery.
-If there's a floppy plastic cover on the glovebox, unclip it from the rear of the glovebox and flop it toward you to get it out of the way. Luckily, you don't have to remove the plastic fasteners on the near edge.
-If there's a hard plastic cover under the ECU held on with a thick rubber band, remove it. (I don't think you really have to do this now, but I did.)
-Unbolt the ECU. The ECU is held in with four bolts (two in front, two in back). You can see three bolts on the side toward you. Undo the rightmost two (your right). Same with the other side of the ECU.
-Remove the electrical connector on the left of the ECU. To do this, push back on the metal tab at the far end of the connector to free that end, then pivot the connector off, toward you. It's held on fairly tightly. The near end has a retaining tab, which is why you have to pivot it to remove it.

Just a couple of notes about the ECU.
-The ECU is a computer system, with a processor, memory, and I/O. As such, it's sensitive to static electricity, so take appropriate measures to avoid zapping it.
-NOTE WHICH WAY AROUND THE OLD IC IS, SO YOU CAN ORIENT THE NEW ONE CORRECTLY! The end with pin 1 usually has an indentation or notch of some sort.
-When removing a socketed IC (the old chip, for example), use a chip puller, or GENTLY pry each end of the IC out of the socket with a screwdriver, a little at a time. You want to EASE the chip out. If you pry too hard, it will POP out and bend its pins. If you pry with your thumb, chances are you'll skewer yourself on the pins.
-When inserting an IC into a socket, make sure the pins are all straight and resting above their respective socket holes. ALSO MAKE SURE THE CHIP IS THE RIGHT WAY AROUND! Then push down evenly on both ends to seat the chip. Make sure all the pins went into their sockets and didn't buckle instead.

HTH

I bought a used Jim C. chip but didn't get any paperwork. How do I install? Any operating precautions?

Bently doesn't seem to have much other than the ECU is behind the glovebox .....

Many thanks in advance

Eddie

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