E63: No passenger occupancy sensor connection for bypass
Discussion
Hi chaps,
Bit of bother with airbag warning light that I've mentioned here associated with this error code:
Suggests common fault with the passenger occupancy sensor and one option it to purchase a bypass/emulator.
All the write ups suggest a straightforward plug and play installation...if you can find the connector...which I cannot.
View under the seat:
From various write ups looked like I was trying to find a connector towards the back of the seat with red/white/brown wires.
The grey insulated bundle I think is the correct one.
I tried to trace it back up into the seat base to locate the connector, but it seems to attach directly to the sensor itself. Consequently I thought perhaps I had to plug the emulator directly into the yellow block so took the cover off to see what's what.
As you can see, the red/white/brown wire is there but the connector is a lot wider than the connector that came with my bypass kit.
As such my connector (as below) won't fit:
RealOEM only lists the sensor itself for my E63
Whereas for the earlier 645Ci, it also has all the additional connection bits and pieces as expected.
I presume I'd I need to cut and solder the wires from the emulator into that wider connector for this to work? Or do they make kits with this seemingly 'wider' connector that fit directly into the yellow block?
Am I actually looking in totally the wrong place?
Any help much appreciated as I'm starting to get sick of the 'warning ding' on starting the car.
Bit of bother with airbag warning light that I've mentioned here associated with this error code:
Suggests common fault with the passenger occupancy sensor and one option it to purchase a bypass/emulator.
All the write ups suggest a straightforward plug and play installation...if you can find the connector...which I cannot.
View under the seat:
From various write ups looked like I was trying to find a connector towards the back of the seat with red/white/brown wires.
The grey insulated bundle I think is the correct one.
I tried to trace it back up into the seat base to locate the connector, but it seems to attach directly to the sensor itself. Consequently I thought perhaps I had to plug the emulator directly into the yellow block so took the cover off to see what's what.
As you can see, the red/white/brown wire is there but the connector is a lot wider than the connector that came with my bypass kit.
As such my connector (as below) won't fit:
RealOEM only lists the sensor itself for my E63
Whereas for the earlier 645Ci, it also has all the additional connection bits and pieces as expected.
I presume I'd I need to cut and solder the wires from the emulator into that wider connector for this to work? Or do they make kits with this seemingly 'wider' connector that fit directly into the yellow block?
Am I actually looking in totally the wrong place?
Any help much appreciated as I'm starting to get sick of the 'warning ding' on starting the car.
Edited by g3org3y on Sunday 18th October 16:33
I had a similar problem in a 645, and it's worth remembering that the seat occupancy sensor error also picks up the battery isolation mechanism. In the end I removed, cleaned and replugged all the connections in the yellow block under the passenger seat, and then cleaned and reconnected all the battery connections. As I recall there was a thin wire that went across the battery compartment that I had previously disconnected without reconnecting. Reconnecting that cleared the error. It might be worth seeing if you can get access to a similar model to compare the wiring side by side.
To conclude this. With the MOT coming up on the 630i, was important I get this sorted.
Indeed the design of the occupancy sensor was changed during the E63 life cycle.
Appears the 645Ci had the earlier type with the additional bridging cable allowing the plugging in of the emulator. Part number is: 65776924783 and that additional wiring is: 61126939372
The 630i has the later occupancy sensor which is one piece cable that plugs into the yellow black connector. Part number is: 65776982976 and according to ReaOEM is fitted to cars FROM 09/2005.
Although the error code suggested communication problem, my concern was an issue with the sensor mat itself necessitating replacement of the whole thing (costly and time consuming).
I used the my Creator 310 to verify the occupancy sensor was actually working. You can get live data with this code reader so you can see if it activates if someone is sitting on the seat. Fortunately, occupancy sensor itself seemed to be working fine.
It appears that my issue was at the yellow/black connection box itself. The grey insulated cable is from the the occupancy sensor. As mentioned in the OP, has the 3 wires (red, white, brown).
I opened up the connector box and found the pins to be quite oxidised. Cleaned the connections with electrical contact cleaner, fiddled the cables a bit and it has been ok ever since (probably a couple of months now).
MOT passed with no airbag light so I'm very happy. Fingers crossed no further issues. I really hated that bloody 'bong' when getting in the car.
Indeed the design of the occupancy sensor was changed during the E63 life cycle.
Appears the 645Ci had the earlier type with the additional bridging cable allowing the plugging in of the emulator. Part number is: 65776924783 and that additional wiring is: 61126939372
The 630i has the later occupancy sensor which is one piece cable that plugs into the yellow black connector. Part number is: 65776982976 and according to ReaOEM is fitted to cars FROM 09/2005.
Although the error code suggested communication problem, my concern was an issue with the sensor mat itself necessitating replacement of the whole thing (costly and time consuming).
I used the my Creator 310 to verify the occupancy sensor was actually working. You can get live data with this code reader so you can see if it activates if someone is sitting on the seat. Fortunately, occupancy sensor itself seemed to be working fine.
It appears that my issue was at the yellow/black connection box itself. The grey insulated cable is from the the occupancy sensor. As mentioned in the OP, has the 3 wires (red, white, brown).
I opened up the connector box and found the pins to be quite oxidised. Cleaned the connections with electrical contact cleaner, fiddled the cables a bit and it has been ok ever since (probably a couple of months now).
MOT passed with no airbag light so I'm very happy. Fingers crossed no further issues. I really hated that bloody 'bong' when getting in the car.
Edited by g3org3y on Saturday 24th July 17:21
pmorg4 said:
Good work, nothing quite as satisfying as a free repair aside from a few hours of your time and some smart thinking 
Thanks pmorg4. 
I thought it was worth documenting as I couldn't find any other threads online relating to this newer style occupancy sensor. Hopefully will be able to help others who run into similar trouble.
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