Here's a link I found. It is specific to the 06 model but you can search for your own model.

Bmw X5 2006 - Air bags - car safety information, failing parts, recalls, bulletins, complaints

Here's the text:
Bmw is conducting a safety recall campaign on approximately 200,000 my04 through my06 subject vehicles built through 11/30/05 to correct the front passenger seat air bag occupant detection mat. the specific vehicles included in the recall aremy04- 06/ 5-series with standard and sport seats, my04-06/ x3-series and my06/ 3-series with sport seats. in addition, bmw will extend the warranty coverage of the passenger seat air bag occupant detection mat to 10-year/unlimited mileage on approximately 120,000 remaining my04-06 subject vehicles built through 11/30/05. the specific vehicles included in the extended warranty are my 06/ 6 series, my 06/ 3-series with standard seats, my04-05/ z4, my04-06/ 7 series, my 06/ x5, and my04-06/ 5-series with comfort seats.the average frequency of failures among the extended warranty groups was less than 1/7th of the recall vehicle groups.please see bmw's 08v-384 recall notification for further detailsdepending on seat configuration and vehicle geometry, the occupant detection mat can fatigue during use depending on the manner and frequency of the front passenger's entry and exit.specifically, over time, micro-cracks could develop in the side flanks of the mat causing a broken circuit.a brokencircuit can lead to the deactivation of the passenger air bag and the illumination of both the air bag warning light and the passenger air bag light.

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