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MULTIPLE RESTRAINT SYSTEM (MRS III)
INTRODUCTION
The X5 is equipped with the Multiple Restraint System (MRS III) which employs the use of
“SMART” technology. Smart technology refers to the control module’s programming which
allows for the deployment of the airbags, in stages, depending on the s\
everity of the
impact. Two stage airbags are used for both the driver and front passenger which allows
for a softer cushioning effect when the bags are triggered at lighter impacts.
The MRS III system is installed in E38/E39 and E46 Sedan vehicles as of \
3/99 p roduction
and in E46 Coupes as of 6/99 production.
MRS III control modules are manufactured by either Bosch or Temic. While the functional
operation of both modules are the same. The control modules are not interchangeable from
a replacement standpoint. Always refer to the EPC parts system to ensure that the proper
module is installed in the vehicle.
In addition to the use of two stage airbags for the driver and passenger\
, the following fea-
tures are also included in the MRS III system:
• The MRS III control module is linked to the K-Bus for coding and diagnosis.
• The MRS III includes a fuel pump cut off feature in the event of an airbag deployment.
• Inert gas generators are now used for all air bags and seat belt tensioners.
• The inert gas is a mixtu re of hyd rogen (13.5%) and oxygen (8 6.5%).
