Occupancy Sensor and SRS Light

[ThrasherFan]

Wondering if anyone has attempted to replace the occupancy sensor mat on the front passenger seat in their X5. My airebag light went on and the Peake tool I bought indicates it's the sensor. Oddly enough I just replaced the same sensor on my M3. I'm pretty sure it will be about the same approach, but just wanted to check to see if anyone else has tried. If not I'll take pictures and write up something for the DIY'ers. If it's similar to the M3, the part costs around $100 from the dealer but the labor is 3-4 hrs which is an easy few hundred bucks to save if you can do it yourself. No special tools are involved, just a lot of patience.

[ThrasherFan]

Changed the sensor mat and eliminated the airbag warning light and would be happy to post the process I went thru with pictures if anyone is interested. I do need help in figuring out how to post pictures (I may not have enough posts to include a picture??).

Anyway, took about 4 hrs and $110 in parts (sensor mat + clips from dealer) with the most difficult part being the removal and replacement of wire clips that secure the leather to the seat. Pretty easy $250-400 labor savings if/when this thing fails. You will need to have the SRS code read and the warning light reset which does require a special tool that is available from Peake Research for $119. My indepenadant would do the read but would not reset claiming legal liability issues since they didn't do the repair - makes sense I guess. I had purchased the tool since I needed it for the same repair on my M3. I plan to keep it, but could sell it pretty easily on ebay and get most of the cost recovered.

Anyway, little help with how to post pictures and I'll post the DIY.

[msammy]

Originally Posted by ThrasherFan

Changed the sensor mat and eliminated the airbag warning light and would be happy to post the process I went thru with pictures if anyone is interested. I do need help in figuring out how to post pictures (I may not have enough posts to include a picture??).

Anyway, took about 4 hrs and $110 in parts (sensor mat + clips from dealer) with the most difficult part being the removal and replacement of wire clips that secure the leather to the seat. Pretty easy $250-400 labor savings if/when this thing fails. You will need to have the SRS code read and the warning light reset which does require a special tool that is available from Peake Research for $119. My indepenadant would do the read but would not reset claiming legal liability issues since they didn't do the repair - makes sense I guess. I had purchased the tool since I needed it for the same repair on my M3. I plan to keep it, but could sell it pretty easily on ebay and get most of the cost recovered.

Anyway, little help with how to post pictures and I'll post the DIY.

Nice work ThrasherFan! You can post pics by first loading them onto your PC, then do a new post to this thread and scroll to the bottom of the screen to the "Additional Options" section. Click on the "Manage Attachments" button and select the directory & photos you'd like to post. Thanks for posting the info - I'm sure this will come in handy for me and others in the future.

[ThrasherFan]

Thanks for the help msammy. Following was my approach.

Parts: Fig 1a/b

• Sensor Mat - Part 3 on Fig 1a ,BMW part no. 65-77-6-921-952
• Control Unit - Part 4 on Fig 1a, BMW part no. 65-77-6-940-191
• Fastening Clips (get at least 15) - Part 6 on Fig 1b, BMW part no. 52-10-945-543
• Note depending upon the code that is thrown you may need only need the mat or the control unit. Using the Peake reaseacrh R5/SR5 tool, if code points you to Occupancy Senor II, you only need the control module. If it points to just Occupancy Senor you only need Sensor Mat. In my case both codes were thrown so I needed both.

Tools and Workbench: Fig 2

• 17mm socket, 1/4 drive ratchet, 3" extension
• Screwdriver with torx bits, T20, T25, T30
• 2 sets of pliers - longer is better as you'll find when it comes to dealing with the clips that hold leather in place
• 19mm socket and 3/8" drive if you want to disconnect - I ended up not doing this with no ill effects
• Blanket to protect when removing seat from vehicle
• Workbench - I found a normal height workbench to be uncomfortable to work on the seat. This saw horse set up with plywood made it much easier to get at things and move seat around for easier access to the clips that you'll learn to hate.

Seat Removal: Fig 3-9

• Slide seat back to expose nut caps/nuts securing from of seat rails to floor. Remove nut caps and nuts - Fig 3
• Slide seat forward and adjust seat forward to expose bolts securing rear of seat rails to floor. Remove bolts - Fig 4
• Slide seat forward and raise seat to highest level to expsose nut securing seat belt to floor. Remove nut - Fig 5
• Lean seat back to expose electricl connection - Fig 6
• Disconnect electrical by sliding black clasp - Fig 7 closed, Fig 8 open
• Lay blanket in door well to protect finish from damage - Fig 9
• With seat still in leaned back position, pick up the seat (to avoid dragging on carpet) and move forward while at same time turning seat to face door. From get a good hold on seat and left out of vehicle. Seat weighs about 50 lbs so get help if you need. last thing you want is to scratch anything on the rails the seat rides on have some sharp edges.

Continued...

[ThrasherFan]

Trim Removal: Fig 10-13

• Place seat as shown in Fig 10. The circled part is the control unit. Disconnect the wire that goes to sensor mat. Twist the control unit to remove from mounting bracket and replace if necessary.
• Fig 11 shows the trim with the electric seat adjustment levers removed from seat. The circled areas indicate where there are plastic tabs that secure the trim to the seat. Carefully lift/manuever these tabs to be able to separate from seat. Take your time here and work with enough force to free the tabs but not so much force to break them. You can then remove the seat control module from the trim if you want by gently lifting the tabs that secure the control module to the trim - there are 4. It will make it easier to move the seat around for later steps.
• Once the above trim is removed, remove the 4 bolts (3 black, 1 bronze) from the mounting brack that the trim was secured to - Fig 12
• Now you will be able to access another piece of trim as shown on Fig 13. Remove the two screws on each side of the seat - the screw on one side is shown.
• You need to go through all the above to be able to remove the leather from the seat.

Detaching Leather from seat frame: Fig 13-16

• Detach spring at the back part of seat from frame by pushing the springs and plastic sleeve forward, into seat, they just sit in the metal tabe by tension. There are 4 or 5 places where the seat spring attaches. One is shown in Fig 14.
• Remove 2 screws from each side of seat that hold the metal frame that the seat leather is attached to - Fig 15. You do not need to remove this piece once the screws are removed. This will provide slack in the leather to fish the sensor mat wire connection through.
• Now you can detach the leather from the seat frame. Compress the cussion to give you some slack and peel the plastic mounting channel away from the frame as shown in Fig 16.

Continued

[ThrasherFan]

Thigh Support Leather Detach: Fig 17-19

• Pry open the metal tabs that secure the leather to the thigh support - Fig 17. There are a total of three with one being right under the grip that you use to extend/retract the support.
• Peel the leather away from the support frame - Fig 18
• Fig 19 shows the thigh support cushion which you can now set aside while you continue to the next steps

Leather Fastening Clips - the real PITA part!: Fig 20-23

• Fig 20 shows the approximate location of the wire fastening clips that you need to remove in order to access the sensor mat.
• Fig 21-23 show these clips in various states of removal. You'll see that each clip wraps around wire straps that are molded into the seat foanm and sewn into the leather. I found the best way to get at these to remove was with 2 pair of pliers, pulling the fastener apart enough to remove from the wre straps. I used one pair of pliers to replace and found it helpful to partially close the clips before clamping closed. Unless you have some upholstry experience, I found this part of the job the most frustrating. I'm sure there must be a tool that upholsterers use to make this removal/replacement easier. I found you can be somewhat aggressive to get the pliers in the right position to clamp the fasteners closed , but just be careful you don't do too much damage to the seat cushion.

Sensor Mat: Fig 24
Well all the work up to now, is just to get at the problem sensor mat. Now that the leather is loose, you should be able to remove the old mat and position the new one in place. Be careful to ensure you push the part of sensor mat into the groves between the two cushion sections. Fish the wire connector thru the hole in the back of the seat cushion and reonnect to the control module.

From here it's everything in reverse to button things back up. You'll need to get a Peake tool to reset the code, or find someone who can/will reset it for you. Otherwise the airbag light will not go out.

Just noticed that the Figure numbers and picture titles didn't come up. I probably also should have formatted the pictures to be smaller. Hopefully you'll be able to follow the pictures based on the description since they are posted in the order that I refer to them in, and that the size doesn't make them too hard to navigate.

Good luck for anyone else who tries this. I guess I should mention that I take no responsibility or assume no liability for anything that happens to anyone or any vehicle they work on as a result of following the above process.

[xnsf]

wow...so detailed. all that work just to replace a sensor?

great write-up

[msammy]

Holy crap ThrasherFan, when you said you'd post a few photos, this wasn't what I had in mind! Excellent and thorough work. I will definitely bookmark this thread for the future. Thanks for posting and it's great work like yours that help others and keep X5world the best forum for X5 lovers!

[ThrasherFan]

Yeah...I prolly went a little overboard on details and pix. My attempt at pay forward for someone who may want to try this DIY. I also prolly made it look/sound worse than the job really is. MY whole motivation was to avoid handing a well paid mechanic some decent money for a repair that did nothing to enahance handling, performance, longevity etc etc.

Also, I was told that when the airbag light is on, the SRS system (or maybe it was just the airbags) is disabled and I wanted both the light off and the SRS system to work if/when needed.

Anyway - hope this helps others.

[tonycajjo]

did anything have to be reset after everything was replaced. i want to remove my seat to see whats going on under there with the previous owners dvd installiation. In my freinds acura when we removed the seat we had to go to his shop, hook up to the computer to re-enable the air bags. does this not apply to the X5?

ADDED:
nevermind, found that if i remove the battery prior to disconnecting anything i should be fine.

(p.s. i did search for seat removal but found nothing, then i searched for airbag info again and found what i was lookin for.)