ignition BMW 7 SERIES 1999 E38 MRSIII Multiple Restraint System Manual

5
COMPONENTS
DRIVER’S FRONT AIRBAG
With the MRS III system, the driver’s front airbag becomes a two stage bag similar to the
passenger’s front side bag, introduced on the 1999 model E38/E39s. The complete
assembly is mounted beneath the cover in the center of the steering whee\
l as with previ-
ous airbags. The assembly now contains the inert gas generator chamber a\
nd two ignition
stages (ignitors).The airbag consists of:
• Accumulator/gas generator
• Two ignition capsules
• Propellant gas - 13.5% hydrogen/86.5% oxygen
• 64 liter airbag

6
COMPONENTS
PASSENGER’S FRONT AIRBAG
The passenger’s front airbag is the same unit as installed on E38/E39 vehicles as of 9/98
production. The passenger’s airbag consists of:
• Pressure accumulator/gas generator
• Two ignition capsules - for two stage activation
• Propellant gas of - 13.5% hydrogen/86.5% oxygen
• 105 liter airbag
PRESSURE ACCUMULATOR
IGNITION CAPSULES

15
DIAGNOSIS
Diagnosis and troubleshooting of the MRS III system is fault driven and can be accessed
using the DIS Tester or MoDiC. The control module performs a self test of the system every
time the ignition is switched on ( this includes the satellite sensors and seat occupancy sen-
sor). Any faults with the system will cause the warning lamp in the instrument cluster to
remain illuminated after the engine is started.
Installation of a new or replacement control module requires ZCS coding also using the DIS
or MoDiC.
When servicing or replacing any MRS III components, always follow precautionary mea-
sures outlined in the repair manual of TIS. this includes disconnecting the battery prior to
any repair or maintenance work being performed.
All airbag components are part number specific by model and require verification in the
EPC to ensure the correct component is being installed.