A common fault with BMW is the airbag warning light. A warning symbol comes on in the instrument cluster along with a message that explains the Control Check message. Detailed below are the fault lights Check Control message and explanation messages in the instrument cluster for the BMW 3 series.
| Control unit | ID code | Fixed indicator light | Variable indicator light | Check Control message | Message in Central Information Display |
|---|---|---|---|---|---|
| MRS | 92 |  | | Front passenger restraint system faulty! | Passenger seat belt. Seat belt pretensioner or seat belt force limiter malfunction. Ensure your seat belt is fastened despite the fault! Have the problem checked by the nearest BMW Service. |
| MRS | 93 | | | Driver restraint system faulty! | Driver's seat belt. Seat belt pretensioner or seat belt force limiter malfunction. Ensure your seat belt is fastened despite the fault! Have the problem checked by the nearest BMW Service. |
| MRS | 94 | | | Restraint system, rear left, faulty! | Left seat belt in rear compartment. Seat belt pretensioner malfunction. Ensure your seat belt is fastened despite the fault! Have the problem checked by the nearest BMW Service. |
| MRS | 95 | | | Restraint system, rear right, faulty! | Right seat belt in rear compartment. Seat belt pretensioner malfunction. Ensure your seat belt is fastened despite the fault! Have the problem checked by the nearest BMW Service. |
| MRS | 97 |  |  | Restraint systems malfunction! | Restraint systems. Function of airbags, seat belt pretensioner and belt force limiter faulty. Ensure your seat belt is fastened despite the fault! Have the problem checked by the nearest BMW Service. |
| MRS | 106 | | | Rear left side airbag faulty! | Left rear compartment airbag. Side airbag faulty. Do not use left rear seat if possible. Have the problem checked by the nearest BMW Service. |
| MRS | 107 | | | Side airbag, rear right faulty! | Right rear compartment airbag. Side airbag faulty. Do not use right rear seat if possible. Have the problem checked by the nearest BMW Service. |
| MRS | 108 | | | Driver airbags faulty! | Driver airbags. Airbag malfunction. Have the problem checked by the nearest BMW Service. |
| MRS | 109 | | | Front passenger airbags faulty! | Passenger airbags. Airbag malfunction. If possible leave front passenger seat unoccupied. Have the problem checked by the nearest BMW Service. |
BMW 3 Series Common Airbag Faults
It’s difficult to establish the exact fault without connecting diagnostic equipment. There are however common faults that trigger the warning lamp.
Passenger Seat Sensor
The most common fault is related to the passenger seat weight sensor. This sensor is located under the passenger seat cushion and is designed to detect passenger weight. The system determines whether the airbag is deployed event of a collision. This system is designed to protect children who can be inured from airbags.
To repair the faulty mat sensor requires the removal of the seat, though before doing so, check for any loose cable connections under the seat. If the seat is frequently moved, connections can become lose. Alternatively, a quick-fix option is to purchase an emulator which enables the system to a working condition, it is MOT compliant and is easily attached.
Seat Belt Buckle
Another possibility for the airbag light staying on is the seat belt buckle, or rather the switch inside the buckle. The buckle may need replacing due to wear-and tear, alternatively something small may have lodged inside. When seated and with the ignition on, try wiggling the latch to see if the airbag light goes out.