How I Replaced my Passenger Occupancy Sensor - The 7 Series (E38) Message Board

No “formal” DIY instructions, but I can tell you how I did mine a couple weeks ago. Note to next person who does this: Take pictures. Feel free to use my text if needed.

Get a Peake Research SRS Tool. A must. No option. Buy one from them on line, or on ebay.

Raise the seat as high as it will go. Check all the wiring under the seat to verify the connectors are well connected.

Use the tool to check what the problem is. Could be a number of things besides the Passenger Occupancy Sensor. Try resetting it and seeing if it comes back. A one-time fault will keep the SRS light on.

Remove the four bolts that hold the seat down to the floor. You’ll need a TORX socket.

Using the power, lower the seat again, and move the back all the way upright, and the heardrest down. This will aid in getting it out of the car.

Disconnect the wiring connectors. They have slides, etc., and come apart easily when you figure out how.

Disconnect the cable that moves the shoulder harness up as the seat goes forward.

Disconnect the seat belt holder on the seat, toward the door.

Lift the seat out the front door. It’s not too heavy, but bulky with sharp metal at the base. A friend is a good insurance policy against a ripped dash or door.

Set the seat down somewhere clean and comfortable. I put car wash towels on the living room floor and sat it there.

Remove the plastic panels along the sides of the seat bottom. Disconnect the switches.

Rest the seat on it’s back.

Congratulate yourself on completing the easy and non-scary part. Remove 6 pack of beer from refrigerator. Take two, one for you, and one for friend who helped carry seat. Be sure to reinstall beer in refrigerator immediately.

Remove the leather from the seat cushion. There are metal tabs that run through holes in the leather, and are bent over. Straighten them to the point the leather can be pulled over them. Push down on the cushion to get enough slack. Do not, under any circumstances, allow the leather to tear. I disconnected the leather all the way around the base.

Now the skill part. Carefully lift the leather up the sides, without pulling on the seat surface. The seating surface is held in place by hog’s rings that capture firm wires on the leather, and in the foam. Either get a set of hog ring tools (upholstery shops have them), or use a variety of needle nose pliers to open them.

You should now be able to carefully remove the sensor assembly.
I tend to be paranoid about these things, so I then laid the leather back over the top, and carried the seat back to the car, placing it in the approximate location. Rehooked the wires, and started the car. Reset the SRS light, and it stayed off. Sat on the seat. Still off. Turned off the car, disconnected the wires, and brought the seat back inside.

Use a great deal of care (and time) in this part. It’s critical. Re attach the hogs rings. Make sure they close and don’t allow the held wires to come out. Again, needle nose pliers, time, and hurt fingers will get you there.

Reconnect the switches. Reinstall the sidepieces. Put the seat back in the car. Reattach the wires, and recheck that it all works. Reattach the shoulder harness cable. Rebolt the seat into place.

Remove remaining 4 beers from fridge, and celebrate a job well done. You saved a small fortune.