wiring MERCEDES-BENZ ML320 1997 Complete User Guide

Fig. 34: Air Bag System Wiring Diagram (SLK230)

1998 Mercedes-Benz ML320
AIR BAG RESTRAINT SYSTEM 1998 AIR BAG RESTRAINT SYSTEMS Mercedes-Benz
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63 Restraint systems
Te ch n ica l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index Safety guidelines for the seat belt,
emergency tensioning retractor and airbag
Wa r n i n g !
• Damaged seat belts or belts that were highly
stressed in an accident must be replaced and
their anchoring points must also be checked.
Use only belts installed or supplied by an
authorized Mercedes-Benz Light Truck Center.• Do not pass belts over sharp edges.• Do not make any modification that could
change the effectiveness of the belts.• Airbags and ETR’s are designed to function on
a one-time-only basis. An airbag or emergency
tensioning retractor (ETR) that was activated
must be replaced.
• An airbag system component within the
steering wheel gets hot after the airbag has
inflated. Do not touch.• Improper work on the system, including
incorrect installation and removal, can lead to
possible injury through an unintended
activation of the “SRS”.• No modifications of any kind may be made to
any components or wiring of the “SRS”. This
includes changing or removing any component
or part of the “SRS”, the installation of
additional trim material, badges etc. over the
steering wheel hub, front passenger airbag
cover, or front door trim panels, and
installation of additional electrical / electronic
equipment on or near “SRS” components and
wiring. Keep area between airbags and
occupants free of objects (e.g. packages,
purses, umbrellas, etc.).

181 Driving instructions
Te ch n ica l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index Winter driving
Have your vehicle winterized at your authorized
Mercedes-Benz Light Truck Center before the onset of
winter.
•Change the engine oil if the engine contains an oil
which is not approved for winter operation. For
viscosity (SAE / CCMC class) and filling quantity,
see page 292.
•Check engine coolant anticorrosion / antifreeze
concentration.
•Additive for the windshield washer and headlamp
cleaning system: Add MB Concentrate “S” to a
premixed windshield washer solvent / antifreeze
which is formulated for below freezing temperatures
see page 237.
•Test battery: Battery capacity drops with decreasing
ambient temperature. A well charged battery helps
to ensure that the engine can be started, even at low
ambient temperatures.
•Tires: We recommend M+S rated radial-ply tires on
all four wheels for the winter season. Observe
permissible maximum speed for M+S rated
radial-ply tires and the legal speed limit.In winter operation, the maximum effectiveness of the
antilock brake system (ABS), the four wheel electronic
traction system (4-ETS+), the electronic stability
program (ESP), and electronic brake proportioning
(EBP) can only be achieved with M+S rated radial-ply
tires and / or snow chains recommended by
Mercedes-Benz. Snow chains maximize performance.
For driving instructions using snow chains see
page 179.
Deep water
Caution!
Do not drive through flooded areas or water of unknown
depth. Before driving through water, determine its
depth. It should not be deeper than approximately
20 inches (50 cm).
If you must drive through deep water, drive slowly to
prevent water from entering the engine compartment or
passenger compartment, being ingested by the air
intake, possibly causing damage to electrical
components or wiring, to engine or transmission that is
not covered by the Mercedes-Benz Limited Warranty.

191 Driving instructions
Te ch n ica l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index Electrical connections
The vehicle is prewired to accept the seven-wire harness
included in the Mercedes-Benz approved trailer hitch
receiver kit. An additional four-pole conversion plug is
included in the Mercedes-Benz supplied trailer hitch
receiver kit. For further information, please see your
authorized Mercedes-Benz Light Truck Center.
In order to prevent possible damage to the vehicle’s
electrical system by incorrectly installing the trailer
wiring plug, we recommend having the harness
connected at an authorized Mercedes-Benz Light Truck
Center.Vehicle and trailer weights and ratings
Gross Vehicle Weight Rating (GVWR) is the maximum
permissible vehicle weight: 6005 lbs. (2724 kg)
Gross Vehicle Weight (GVW): comprises weight of
vehicle including fuel, tools, spare wheel, installed
accessories, passengers, cargo and trailer tongue. It
must never exceed the GVWR.
Gross Axle Weight Rating (GAWR) is the maximum
permissible axle weight:
Gross Trailer Weight (GTW) is the maximum
permissible trailer weight to be towed:
5000 lbs. (2260 kg)
Trailer Tongue Weight Rating (TWR) is the maximum
permissible weight of the trailer tongue:
[500 lbs. (225 kg) limit for MB approved hitch receiver] front
rear2755 lbs.
3527 lbs.(1250 kg)
(1600 kg)

193 Driving instructions
Te ch n ica l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index Attaching a trailer
Please observe maximum permitted trailer dimensions
(width and length).
Most states and all Canadian provinces require safety
chains between your tow vehicle and the trailer. The
chains should be crisscrossed under the trailer tongue.
They must be attached to the hitch receiver, and not to
the vehicle’s bumper or axle. Be sure to leave enough
slack in the chains to permit turning corners.
Most states and all Canadian provinces require a
separate brake system at various trailer weights.Caution!
Do not connect a trailer brake system (if trailer is so
equipped) directly to the vehicle’s hydraulic brake
system, as your vehicle is equipped with antilock
brakes. If you do, neither the vehicle’s brakes nor the
trailer’s brakes will function properly.
The provided vehicle electrical wiring harness for trailer
towing has a brake signal wire (color orange) for
hook-up to a brake controller.
Most states and all Canadian provinces require a
break-away switch on trailers with a separate brake
system. The switch activates the trailer brakes in the
possible event that the trailer might separate from the
tow vehicle.
You should consider using a trailer sway control system.
For further information see your authorized
Mercedes-Benz Light Truck Center.

2000-01 ACCESSORIES/SA FETY EQUIPMENT
Mercedes-Benz - Air Bag Restraint Systems
DESCRIPTION & OPERATION
All models are equipped with Supplemental Restraint Syst em (SRS). The main components of SRS are driver-
side air bag module, passenger-side air bag module, si de air bag modules (located in doors), SRS control
module, side air bag sensors, SRS warning light, driver knee bolster, pa ssenger knee bolster, and Emergency
Tensioning Retractor (ETR) seat belt assembly. Additionally, some vehicles may be equipped with head impact
(curtain type) air bags (located ar ound door windows behind door frame trims).
Both SRS and ETR are electronically activated by a single control module. There are 2 thresholds which must
be exceeded to trigger an ETR acti on, air bag deployment, or both. If a moderately severe frontal collision
occurs exceeding first triggering thre shold 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 ETR is not activated.
If a severe frontal collision occurs exceeding second triggering threshold where protection from safety belt is
insufficient, air bag is deploye d. ETR 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 thre shold 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 th e driver-side air bag module is deployed and when there
is a substantial side impact crash. The air bag on the pa ssenger-side will activate only when a sensor (Occupied
Seat Recognition Sensor) in the passenger seat sends a si gnal to the SRS control module that the passenger-side
seat is occupied. During a collision, the side air bag will then deploy.
COMPONENT LOCATIONS NOTE: The following 2000 in
formation represents the latest information available at
time of publication and m ay be useful in diagnosing 2001 vehicles. 2001 wiring
diagrams have been included at the end of this article.
WARNING: Accidental air bag deployment is pos sible. Personal injury may result.
Read and follow all WARNINGS and AIR BAG SAFETY PRECAUTIONS

before working on ai r bag system or related components.

2001 Mercedes-Benz ML320
2000-01 ACCESSORIES/SAFETY EQUIPMENT Merc edes-Benz - Air Bag Restraint Systems

2001 Mercedes-Benz ML320
2000-01 ACCESSORIES/SAFETY EQUIPMENT Mercedes-Benz - Air Bag Restraint Systems
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Fig. 1: Locating Restraint System Components (2000 E Class Shown; Others Are Similar)
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
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 insp ected, 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.
SYSTEM OPERATION CHECK
SRS warning light indicates air ba g and Emergency Tensioning Retracto r (ETR) system readiness. Turn
ignition on. SRS warning light will illuminate, then turn off after approximately 4-20 seconds indicating system
is functioning properly. If SRS warning light does not illuminate, illuminates while driving or is continuously
illuminated, there is a system faul t. Repair malfunctioning system. See DIAGNOSTICS
.
AIR BAG SAFETY PRECAUTIONS
Observe following precautions when working with air bag systems:
When working around steering column components and be fore any repairs are performed, disable air bag
system. See DISABLING & ACTIVATING AIR BAG SYSTEM
.
Before straightening any damage to body, or before performing electrical arc-welding, disable air bag
system. See DISABLING & ACTIVATING AIR BAG SYSTEM
.
Always wear safety glasses and gloves when ha ndling a deployed air bag module. Air bag module may
contain sodium hydroxide deposits wh ich are irritating to the skin.
DO NOT repair any portion of SRS wiring harness.
Always handle air bag module with trim cover away from your body. Always place air bag module on
workbench with trim cover up, away from loose objects.
DO NOT expose any SRS component to temp eratures in excess of 212 F (100 C).
DO NOT expose any SRS component to cleaning agen ts such as solvents, gasoline, lye, etc.
DO NOT connect Hand-Held Tester (6511 0001 99) to Data Link Connector (DLC) with ignition on.
Damage to HHT may result.
DO NOT connect HHT (6511 0001 99) to vehicle if a battery charger is connected to vehicle battery.
Damage to HHT may result.
ADJUSTMENTS
If fixing screws were not used durin g 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 holdi ng clockspring in this position.
DISABLING & ACTIVATI NG AIR BAG SYSTEM

2001 Mercedes-Benz ML320
2000-01 ACCESSORIES/SAFETY EQUIPMENT Merc edes-Benz - Air Bag Restraint Systems
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from front seat. DO NOT allow anyone inside vehicle.
3. Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM
. Connect Trigger
Device (126-589-00-90-00) and Adapter Cable (126 589 21 63 00) to SRS system connector (X29-9)
located at passenger footwell area. Move away from ve hicle as far as trigger device wiring will allow.
4. To deploy driver air bag and ETR, turn rotary knob on trigger device to position No. 1. Push battery
check push button and ignition push button simultane ously. Trigger light should illuminate indicating
driver air bag and ETR deployed. If trigger light is illuminated and driver air bag and-or ETR did not
deploy, driver air bag module and-or ETR is faulty. See UNDEPLOYED AIR BAG
-ETR .
5. To deploy passenger air bag detonator No. 1, turn ro tary knob on trigger device to position No. 2. Push
battery check push button and igni tion push button simultaneously. Tr igger light should illuminate
indicating passenger air bag detonator No. 1 deployed. If trigger light is illuminated and passenger air bag
detonator No. 1 did not deploy, passe nger air bag module is faulty. See UNDEPLOYED AIR BAG
-
ETR .
6. To deploy passenger air bag detonator No. 2, turn ro tary knob on trigger device to position No. 3. Push
battery check push button and igni tion push button simultaneously. Tr igger light should illuminate
indicating passenger air bag detonator No. 2 deployed. If trigger light is illuminated and passenger air bag
detonator No. 2 did not deploy, passe nger air bag module is faulty. See UNDEPLOYED AIR BAG
-
ETR .
UNDEPLOYED AIR BAG-ETR
After deploying procedures and-or diagnostic testing have confirmed air bag module and-or ETR is
undeployable, contact vehicle manufacture r for proper disposal instructions.
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 AIR BAG/SRS COMPONENT INSPECTION & REPLACEMENT TABLES

article in the GENERAL INFORMATION section.
REMOVAL & INSTALLATION
CLOCKSPRING ASSEMBLY
Removal & Installation
1. Before proceeding, See AIR BAG SAFETY PRECAUTIONS . Disable air bag system. See
DISABLING & ACTIVATI NG AIR BAG SYSTEM
.
2. Remove driver air bag module. See DRIVER
-SIDE AIR BAG MODULE . Remove steering wheel bolt.
Using a puller, remove steering wheel. Disconnect lower clockspring connector. Turn 2 fixing screws
(locating on clockspring) countercl ockwise until clockspring cannot be rotated. Remove clockspring
mountin
g screws as necessary. Disconnect all necessary electrical connectors. Remove clockspring
WARNING:
Accidental air bag deployment is pos sible. Personal injury may result.
Read and follow all WARNINGS and AIR BAG SAFETY PRECAUTIONS

before working on ai r bag system or related components.

2001 Mercedes-Benz ML320
2000-01 ACCESSORIES/SAFETY EQUIPMENT Merc edes-Benz - Air Bag Restraint Systems
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Fig. 58: Testing Seat Occupation Recognition Sensor (2000 Models)
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
WIRE REPAIR
If any part of SRS wiring harness is damaged, DO NOT repair wiring harness, replace complete wiring harness.

2001 Mercedes-Benz ML320
2000-01 ACCESSORIES/SAFETY EQUIPMENT Merc edes-Benz - Air Bag Restraint Systems
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TORQUE SPECIFICATIONS
TORQUE SPECIFICATIONS
(1)
WIRING DIAGRAMS
ApplicationFt. Lbs (N.m)
Steering wheel hub bolt52-66 (70-90)
INCH Lbs. (N.m)
Driver air bag module bolts (torx)44-62 (5-7)
(1)Torque specifications are not av ailable for clockspring assembly, control module or passenger-side
air bag module.

2001 Mercedes-Benz ML320
2000-01 ACCESSORIES/SAFETY EQUIPMENT Merc edes-Benz - Air Bag Restraint Systems
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