
Fig. 1: Locating Restraint System Components (E Class Shown; Others Are Similar) 
Courtesy of MERCEDES-BENZ OF NORTH AMERICA 
Both SRS and ETR are electronically activated by a single control unit if a moderately severe to severe frontal 
collision occurs. 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 safety belt is sufficient, only Emergency Tensioning Retractor (ETR) is activated if safety belt is buckled. 
If a moderately severe frontal collision occurs exceeding first triggering threshold where protection from safety 
belt is sufficient, but safety belt is not buckled, air bag is deployed and EAR is not activated. 
If a severe frontal collision occurs exceeding second triggering threshold where protection from safety belt is 
insufficient, air bag is deployed. EAR is activated if safety belt is buckled. If safety 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. If during a severe frontal collision the power supply is 
interrupted, the driver and passenger air bag can still be deployed, but ETR cannot 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 control module that the passenger-side seat 
is occupied. During a collision, the side air bag will then deploy. 
SERVICING 
SRS AIR BAG label on driver-side door latch post indicates SRS replacement date for driver and passenger air 
bag units. All SRS components must be thoroughly inspected, including wiring harness. Before component 
replacement, check for SRS fault codes by performing system operation check. See SYSTEM OPERATION 
CHECK . SRS service life is 10 years from manufactured date, or 10 years from SRS replacement date after 
accident related repairs are completed. 
POST-COLLISION INSPECTION 
When a vehicle has been involved in a collision, certain components of the passive restraint system must be 
inspected or replaced. See PASSIVE RESTRAINT SYSTEM INSPECTION article in the GENERAL 
INFORMATION section for post-collision inspection information. 
ADJUSTMENTS 
If fixing screws were not used during clockspring removal or clockspring was rotated during removal, turn 
clockspring clockwise until resistance is detectable. Turn clockspring counterclockwise 2-2.5 turns until fixing 
screws can be unscrewed holding clockspring in this position. 
DISPOSAL PROCEDURES 
WARNING:An undeployed air bag module or ETR should never be disposed of 
without first being deployed. See SCRAPPED VEHICLE
 . If deployment is 
not possible, contact vehicle manufacturer for further instructions.
 
1998 Mercedes-Benz ML320 
AIR BAG RESTRAINT SYSTEM 1998 AIR BAG RESTRAINT SYSTEMS Mercedes-Benz  
me  
Saturday, October 02, 2010 3:33:13 PMPage 3 © 2006 Mitchell Repair Information Company, LLC.  

20 Instruments and controls
Te ch n ica l
data Instruments 
and controlsOperation DrivingInstrument 
cluster displayPractical hints Car care Index
Center console1Left front seat heater switch, see page 44
2Switch for rear quarter window, left, see page 106
3Switch for rear window washer /wiper, see page 96
4ESP control switch, see page 207
5Switch for rear quarter window, right, see page 106
6Right front seat heater switch, see page 44
7Storage compartment
8Selector lever, see page 165
9Ashtray with lighter, see page 118
10Power window switch, left front door, see page 104
11Central locking switch, see page 32
12Rear window defroster switch, see page 103
13Power window switch, right front door, see page 104
14Power window switch, left rear door, see page 104
15Mirror adjustment switch, see page 73
16Power window safety switch, rear doors, see 
page 104
17Power window switch, right rear door, see page 104 

38 Seats
Te ch n ica l
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index
Important!
Prior to operating the vehicle, the driver should adjust 
the seat height for proper vision as well as fore / aft 
placement and backrest angle to insure adequate 
control, reach, operation, and comfort. The head 
restraint should also be adjusted for proper height. See 
also airbag section on page 56 for proper seat 
positioning.
In addition, also adjust the steering wheel to ensure 
adequate control, reach, operation, and comfort.
Both the inside and outside rear view mirrors should be 
adjusted for adequate rearward vision.
Fasten seat belts. Infants and small children should be 
seated in a properly secured restraint system that 
complies with U.S. Federal Motor Vehicle Safety 
Standard 213 and Canadian Motor Vehicle Safety 
Standard 213.
All seat, head restraint, steering wheel, and rear view 
mirror adjustments as well as fastening of seat belts 
should be done before the vehicle is put into motion.
Wa r n i n g !
Children 12 years old and under must never ride in 
the front seat, except in a Mercedes-Benz 
authorized BabySmart
TM compatible child seat, 
which operates with the BabySmart
TM system 
installed in the vehicle to deactivate the passenger 
side front airbag when it is properly installed. 
Otherwise they will be struck by the airbag when it 
inflates in a crash. If this happens, serious or fatal 
injury can result.
According to accident statistics, children are safer 
when properly restrained in the rear seating 
positions than in the front seating positions. 
Infants and small children must ride in the back 
seats and be seated in an appropriate infant or 
child restraint system, which is properly secured 
with the vehicle’s seat belt, fully in accordance 
with the child seat manufacturer’s instructions.A child’s risk of serious or fatal injuries is 
significantly increased if the child restraints are 
not properly secured in the vehicle and the child is 
not properly secured in the child restraint. 

39 Seats
Te ch n ica l
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index Manual seats (ML 320)
We recommend to adjust the manual seat in the 
following order:
1Seat, fore / aft
Lift handle (1), slide seat to desired position and 
allow handle to reengage. Check for proper 
engagement before driving. The position should be 
as far rearward as possible, consistent with ability to 
properly operate controls.2Seat cushion inclination adjustment
Raise lever (2), move seat cushion to desired 
position. Release lever.
3Backrest adjustment
Turn handwheel (3).
4Head restraint height
Raising: 
Pull up on head restraint.
Lowering: 
Push button (4), located at top of seat back, and 
push down on head restraint.
Adjust head restraint to support the back of the head 
approximately at ear level. The head restraint angle 
can also be adjusted manually.
See page 43 for removing head restraints. 

40 Seats
Te ch n ica l
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index
Power seats (standard; optional on model ML 320)
The slide switches are located on the entry side of each 
front seat base.
Turn key in steering lock to position 1 or 2 (with the 
driver’s or passenger’s door open, the power seats can 
also be operated with the key removed or in steering 
lock position 0).We recommend to adjust the power seat in the following 
order:
1Seat, up / down
Press the switch (up/down direction) until 
comfortable seating position with still sufficient 
headroom is reached.
2Seat adjustment, fore / aft
Press the switch (fore / aft direction) until a 
comfortable seating position is reached that still 
allows you to reach the accelerator / brake pedal 
safely. The position should be as far rearward as 
possible, consistent with ability to properly operate 
controls.
3Seat cushion tilt
Press the switch in the direction of the arrow until 
your legs are lightly supported.
4Backrest tilt
Press the switch in the direction of the arrow until 
your arms are slightly angled when holding the 
steering wheel. 

41 Seats
Te ch n ica l
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index Only minor personal adjustments, as described below, 
should then be required. 
For exterior rear view mirrors, see page 73; 
inside rear view mirror, see page 71; 
steering wheel adjustment, see page 70.
Note:
See page 42 for instructions on storing and recalling the 
seat position.Head restraint
Raising: 
Pull up on head restraint.
Lowering: 
Push button, located at top of seat back, and push down 
on head restraint, see also page 43.
Adjust head restraint to support the back of the head 
approximately at ear level. The head restraint angle can 
also be adjusted manually.
See page 43 for removing head restraints.
Wa r n i n g !
When leaving the vehicle always remove the key 
from the steering lock, and lock your vehicle.The power seats can also be operated with the 
driver’s or passenger door open. Do not leave 
children unattended in the vehicle or with access 
to an unlocked vehicle. Unsupervised use of vehicle 
equipment may cause serious personal injury. 

49 Restraint systems
Te ch n ica l
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index Tighten the lap portion to a snug fit by pulling shoulder 
portion up.
The shoulder portion of the seat belt must be pulled 
snug and checked for snugness immediately after 
engaging it.
Adjust seat belt so that shoulder portion is located as 
close as possible to the middle of your shoulder (it 
should not touch the neck). For this purpose, you can 
adjust the height of the belt outlet. Three positions are 
available.4Button for belt outlet height adjustment
To raise, slide belt height adjustment upward.
To lower, press button (4) and slide belt outlet 
downward.
Caution!
For safety reasons, avoid adjusting the seat or backrest 
into positions which could affect the correct seat belt 
positioning. 

61 Restraint systems
Te ch n ica l
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index
• Sit properly belted in an upright position with 
your back against the backrest.• Adjust the driver’s seat as far as possible 
rearward, still permitting proper operation of 
vehicle controls. The distance from the center 
of the driver’s breastbone to the center of the 
airbag cover on the steering wheel must be at 
least ten inches (25 cm) or more. You should be 
able to accomplish this by a combination of 
adjustments to the seat and steering wheel. If 
you have any problems, please see your 
authorized Mercedes-Benz Light Truck Center.• Do not lean with your head or chest close to the 
steering wheel or dashboard.• Keep hands on the outside of steering wheel 
rim. Placing hands and arms inside the rim 
can increase the risk and potential severity of 
hand / arm injury when the driver front airbag 
inflates.• Adjust the front passenger seat as far as 
possible rearward from the dashboard when 
the seat is occupied.
• Occupants, especially children, should never 
lean their heads in the area of the door where 
the side airbag inflates. This could result in 
serious injuries or death should the airbag be 
triggered. Always sit upright, properly use the 
seatbelts and appropriate size infant or child 
restraint system.• Children 12 years old and under must never 
ride in the front seat, except in a 
Mercedes-Benz authorized BabySmart
TM 
compatible child seat, which operates with the 
BabySmart
TM system installed in the vehicle to 
deactivate the passenger side front airbag 
when it is properly installed. Otherwise they 
will be struck by the airbag when it inflates in 
a crash. If this happens, serious or fatal injury 
can result.
Failure to follow these instructions can result in 
severe or fatal injuries to you or other occupants.