Mercedes-Benz ML320. Manual

2003 ACCESSORIES/SAFETY EQUIPMENT

Mercedes-Benz - Air Bag Restraint Systems

DESCRIPTION & OPERATION

All models are equipped with Supplemental Restraint System (SRS). The main components of SRS are driver-
side air bag module, passenger-side air bag module, side impact air bag modules (located in doors), SRS control
module, side air bag sensors, SRS warning light, driver-side knee bolster, passenger-side knee bolster and seat
belt pretensioners or Emergency Tensioning Retractor (ETR) seat belt assembly. Additionally, some vehicles
may be equipped with head impact (curtain type) air bags.

Both SRS and ETR are electronically activated by a single control module. There are 2 thresholds which must
be exceeded to trigger an ETR action, air bag deployment, or both. If a moderately severe frontal collision
occurs exceeding first triggering threshold where protection from seat belt is sufficient, only Emergency
Tensioning Retractor (ETR) is activated if seat belt is buckled. If a moderately severe frontal collision occurs
exceeding first triggering threshold where protection from seat belt is sufficient, but seat belt is not buckled, air
bag is deployed and ETR is not activated.

If a severe frontal collision occurs exceeding second triggering threshold where protection from seat belt is
insufficient, air bag is deployed. ETR is activated if seat belt is buckled. If seat belt is not buckled, ETR is not
activated when second triggering threshold is reached. Passenger air bag will deploy even if passenger seat is
not occupied when a triggering threshold is exceeded. During certain types of collisions, the air bags will be
deploy, but ETRs will not be activated.

The side air bag on the driver-side deploys whenever the driver-side air bag module is deployed and when there
is a substantial side impact crash. The air bag on the passenger-side will activate only when a sensor (Occupied
Seat Recognition Sensor) in the passenger seat sends a signal to the SRS control module that the passenger-side
seat is occupied. Side air bags mounted in rear doors will deploy when side impacts occur that exceed preset
parameters.

Head impact air bag modules will deploy when certain side impacts occur that exceed preset parameters. Head
impact air bag will deploy independently of other air bags on side of impact.

COMPONENT LOCATIONS

WARNING:

Accidental air bag deployment is possible. Personal injury may result.
Read and follow all WARNINGS and AIR BAG SAFETY PRECAUTIONS
before working on air bag system or related components.

Component

Location

AIR BAG warning light

Instrument Panel Cluster

Clockspring

Under steering wheel

Driver-side air bag module

On steering wheel

Emergency Tensioning Retractor (ETR)

Driver-side & passenger-side lower B- & C-pillars

(1)

2003 Mercedes-Benz ML320

2003 ACCESSORIES/SAFETY EQUIPMENT Mercedes-Benz - Air Bag Restraint Systems

2003 Mercedes-Benz ML320

2003 ACCESSORIES/SAFETY EQUIPMENT Mercedes-Benz - Air Bag Restraint Systems

Mercedes-Benz ML320. Manual - part 37