BeCM Access and Removal
You can access most of the connectors on the BeCM (except those on its left side) by simply removing the seat base trim and, in the case of the front ones, lifting up the carpet. However if you want to take the lid off to perform internal repairs (see below) you need to remove the unit from the vehicle. This involves taking the seat out -- not too bad a job actually. If the seat base trim is already off, you just have to remove the cover from the seat belt bolt beside the transmission tunnel and unclip the seat belt. Then undo the four bolts that secure the seat to the 47-way adjustment mechanism. After that you can lift the seat up a bit for access and disconnect the multiplugs, allowing complete removal.
From the information above you can tell which connector is affected, and the ETM will even tell you which pin. Then by taking the lid off the BeCM (see below) you can trace the connection from the output connector back to the corresponding power transistor or relay.
Dismantling the BeCM
The lid of the BeCM is held on by a lot small screws with miniature torx heads. The ones around the periphery are tapered metal/plastic screws and the others are machine screws. Once you have found a torx bit small enough and removed the screws, the top panel simply lifts off and you can see the top (ie power distribution) board of the BeCM. If you are at all familiar with electronics, the sight of this board will do much to demystify the BeCM, which turns out to