E36 Seat Belt Latch Replacement
The most common cause for an SRS light that either will not turn off or that stays on for about two minutes everytime you stat the car is a faulty seat belt latch sensor. Unfortuntely BMW does not offer a separate sensor, so to fix the problem you must replace the entire latch assembly.
You will need the following parts/tools:
- 16mm socket
- Small Flat Head Screwdriver
- 3/8" Drive Ratchet
- Electrical Tape
- Small Zip Ties
- Wire Snips or Razor Blade
- 3' of 18Ga wire or similar
- Replacement Latch - see your dealer for the correct one
Switch the ignition to off and leave it off the entire time you have the seat out of the car. To be completely safe, disconnect the negative battery terminal.
Slide the seat all the way forward to expose the rear bolts. Remove the bolts with a 16mm socket. Then slide the seat all the way back to expose the front nuts. Pry off the plastic covers over the nuts with a small screwdriver then remove the nuts.
Tip the seat backwards so that the front edge is upwards and the back is laying on the back seat. Reach under and disconnect all wiring running to the seat. The number of plugs will vary from one to four based on the build date and options such as heated seats. Heated seats have two large connectors, latches have a single small connector and some passenger seats have a small connector for an occupancy sensor.
Once the wires are disconnected, tip the seat forward. Fold the seat back forward to make it more compact. Carefully remove the seat from the car, they are HEAVY (~70lbs... even non-powered Vaders!).
NOTE:Later build dates have a "arming" cable attached from the latch to the seat base. Pry up the plastic catch with a screwdriver to remove it. Then unhook the cable's end from the seat base.
Use your 16mm socket to remove the nut that attaches the latch to the seat base. Thread the nut back on to the stud so that it doesn't roll away. Cut the zip ties that are holding the latch wires to the seat bottom.
Tie a length of wire around the end of the latch wire and wrap the knot with electric tape. Pull the latch wire, with the length of wire attached, through the seat bottom. Carefully guide it through as needed. Once the latch wire is pulled through, you'll be left with a length of wire in it's place that will allow you to pull the new latch wire back through easily.
Discard the old latch. Tie and tape the new latch wire to the length of wire that's threaded though the seat. Carefully pull the length of wire back through the seat bottom, feeding the new latch wire allow with it. Secure the new latch wire to the seat bottom with zip ties in the same locations as the original.
Attachnew latch to the seat bottom using your 16mm socket, attach the arming cable if your latch has one. Reinstall the seat in the car, don't forget to reconnect all of the wiring. Reconnect the battery if you disconnected it earlier.
To reset your SRS light you'll either need to take your car to a BMW dealer or use a Peake Research SRS tool. The SRS light will NOT reset itself, even after all faults are repaired, it must be manually reset.
Rear Bolts |
Front Nuts |
Seat Tipped Back |
Heated Seat Connectors |
Good Time to Vacuum! |
Heated Seat and Latch Wires |
Arming Cable |
Pry Up Clip |
Unhook Cable |
Loosen Nut |
Remove Nut |
Remove Latch |
cut Zip Ties |
Tie Wire to Connector |
Wrap with Tape |
Pull Through |
Tie and Tape to New Connector |
Pull Back Through |
Pulled Through |
Secure with Zip Ties |
Attach Arming Cable |
Rearmed |
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