Air Bag Control Module: Testing and Inspection

R50, R52, R53 - Diagnosis of the multiple restraint system
Diagnosis Scope Of The MRS Control Unit
The MRS control unit logs faults in its internal fault memory. The BMW diagnosis system can be used to access the fault memory via the diagnosis connector.
The diagnosis comprises the following:
- Reading identification
- Reading fault memory
- Clearing fault memory
- Diagnosis request: e.g. for checking the function of the seat-belt-lock switch, front-passenger seat-occupancy detector

Note:
Exchange the MRS control unit after 3 crash messages in which the multiple restraint system was triggered.
When the MRS is triggered, the MRS control unit stores data in a non-erasable memory. The data memory is full after 3 crash messages. The airbag indicator light will come on. The MRS control unit must be exchanged.