ignition MERCEDES-BENZ ML320 1997 Complete Repair Manual

Several situations may arise requiring some form of disposal action, including:
Scrapping a vehicle containing a deployed air bag module and/or ETR.
Scrapping a vehicle with a live air bag module and/or ETR.
Disposal of a live but electrically faulty air bag module and/or ETR.
Disposal of a deployed air bag module and/or ETR.
DEPLOYED AIR BAG OR ETR
Deployed air bag module and/or ETR unit can be thrown away. None of its components are reusable. Deployed
air bag module is NOT classified as hazardous material.
SCRAPPED VEHICLE
1. Before proceeding, follow service precautions. See SERVICE PRECAUTIONS . Move vehicle
outdoors to a remote area, away from workshop and other personnel. Disconnect and shield negative
battery cable. Open all vehicle windows and doors.
2. Ensure air bag module is secured to steering wheel, and passenger air bag is secured to dash. Ensure ETR
seat belt assemblies are secured to "B" pillars and all seat belt buckles are latched. Remove loose objects
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. See Fig. 5
. Move away from vehicle 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 pushbutton and ignition pushbutton simultaneously. 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 rotary knob on trigger device to position No. 2. Push
battery check pushbutton and ignition pushbutton simultaneously. Trigger 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, passenger air bag module is faulty. See UNDEPLOYED AIR
BAG/ETR .
6. To deploy passenger air bag detonator No. 2, turn rotary knob on trigger device to position No. 3. Push
battery check pushbutton and ignition pushbutton simultaneously. Trigger 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, passenger air bag module is faulty. See UNDEPLOYED AIR
BAG/ETR . WARNING:An undeployed air bag module and/or ETR seat belt CANNOT be disposed
of without first being deployed. If this is not possible through procedures
outlined below, contact vehicle manufacturer for further instructions.
Perform remote deployment outdoors. Keep personnel at least 20 feet
away.

1998 Mercedes-Benz ML320
AIR BAG RESTRAINT SYSTEM 1998 AIR BAG RESTRAINT SYSTEMS Mercedes-Benz
me
Saturday, October 02, 2010 3:33:13 PMPage 4 © 2006 Mitchell Repair Information Company, LLC.

UNDEPLOYED AIR BAG/ETR
After deploying procedures and/or diagnostic testing have confirmed air bag module and/or ETR is
undeployable, contact vehicle manufacturer for proper disposal instructions.
REMOVAL & INSTALLATION
CLOCKSPRING ASSEMBLY
Removal & Installation
1. Before proceeding, see SERVICE PRECAUTIONS . Disable air bag system. See DISABLING &
ACTIVATING 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) counterclockwise until clockspring cannot be rotated. Remove clockspring
mounting screws as necessary. Disconnect all necessary electrical connectors. Remove clockspring
assembly. To install, reverse removal procedure. Activate air bag system. See DISABLING &
ACTIVATING AIR BAG SYSTEM . Perform system operation check to ensure system is functioning
properly. See SYSTEM OPERATION CHECK
.
CONTROL UNIT
Removal & Installation (C Class)
1. Before proceeding, see SERVICE PRECAUTIONS . Disable air bag system. See DISABLING &
ACTIVATING AIR BAG SYSTEM . Remove ignition key. Remove shift lever cover bezel. Lift shift
lever cover enough to disconnect electrical connector. Remove shift lever cover.
2. Remove storage compartment mounting screws from center console. Remove storage compartment.
Remove ashtray. Disconnect electrical connectors as necessary. Disconnect control module electrical
connector. Remove control module mounting bolts. Remove control module.
3. To install, reverse removal procedure. Ensure control module arrow points to front of vehicle. Set
parameters and program new control module with Hand-Held Tester (965 589 00 01 00). Activate air bag
system. Perform system operation check to ensure system is functioning properly. See SYSTEM
OPERATION CHECK .
Removal & Installation (E Class)
1. Before proceeding, see SERVICE PRECAUTIONS . Disable air bag system. See DISABLING &
ACTIVATING AIR BAG SYSTEM . Remove ignition key. Remove gear shift cover panel. Remove
ashtray and ashtray housing at front of console. Remove radio (if necessary).
2. Remove center console right side cover screws and right side cover. Disconnect electrical connector for
control unit. Remove 2 control unit mounting screws. Remove control unit. WARNING:Failure to follow service precautions may result in air bag deployment and
personal injury. See SERVICE PRECAUTIONS
. After component
replacement, check system operation. See SYSTEM OPERATION CHECK
.

1998 Mercedes-Benz ML320
AIR BAG RESTRAINT SYSTEM 1998 AIR BAG RESTRAINT SYSTEMS Mercedes-Benz
me
Saturday, October 02, 2010 3:33:13 PMPage 5 © 2006 Mitchell Repair Information Company, LLC.

3. To install, reverse removal procedure. Ensure control module arrow points to front of vehicle. Set
parameters and program new control module with Hand-Held Tester (965 589 00 01 00). Activate air bag
system. Perform system operation check to ensure system is functioning properly. See SYSTEM
OPERATION CHECK .
Removal & Installation (S Class)
1. Before proceeding, see SERVICE PRECAUTIONS . Disable air bag system. See DISABLING &
ACTIVATING AIR BAG SYSTEM . Remove ignition key. Remove radio. Remove ashtray. Remove
wooden surround for ashtray. Remove shift lever cover mounting screws. Push shift lever cover toward
rear of vehicle and remove in an upward direction.
2. Remove center console cover screws. Remove center console cover by pulling from bottom in an upward
direction. When removing covers, disconnect electrical connectors as necessary. Disconnect control
module electrical connector. Remove control module.
3. To install, reverse removal procedure. Ensure control module arrow points to front of vehicle. Set
parameters and program new control module with Hand-Held Tester (965 589 00 01 00). Activate air bag
system. Perform system operation check to ensure system is functioning properly. See SYSTEM
OPERATION CHECK .
Removal & Installation (SL Class)
1. Before proceeding, see SERVICE PRECAUTIONS . Disable air bag system. See DISABLING &
ACTIVATING AIR BAG SYSTEM . Remove ignition key. Remove radio. Push up and pull out heater
control panel. Unplug 2 connectors. Remove screw in middle of storage tray.
2. Bend up at top corners and lift out storage tray. Remove screws below storage tray. Lift wood trim panel
at rear, pull down and out of catches. Unplug switch connectors and remove wood trim panel. Unplug
connectors at control unit and remove Torx mounting screws. Remove control unit.
3. To install, reverse removal procedure. Ensure control module arrow points to front of vehicle. Set
parameters and program new control module with Hand-Held Tester (965 589 00 01 00). Activate air bag
system. Perform system operation check to ensure system is functioning properly. See SYSTEM
OPERATION CHECK .
Removal & Installation (CLK 320 & SLK 230)
1. Before proceeding, see SERVICE PRECAUTIONS . Disable air bag system. See DISABLING &
ACTIVATING AIR BAG SYSTEM . Remove ignition key. Remove cover on center console. Remove
cover on shift lever. Remove ash tray housing with storage compartment at front of center console.
Unplug connectors at control unit and remove Torx mounting screws. Remove control unit.
2. To install, reverse removal procedure. Ensure control module arrow points to front of vehicle. Set
parameters and program new control module with Hand-Held Tester (965 589 00 01 00). Activate air bag
system. Perform system operation check to ensure system is functioning properly. See SYSTEM
OPERATION CHECK .
DRIVER-SIDE AIR BAG MODULE
NOTE: Air bag module and steering wheel must be replaced following a collision in

1998 Mercedes-Benz ML320
AIR BAG RESTRAINT SYSTEM 1998 AIR BAG RESTRAINT SYSTEMS Mercedes-Benz
me
Saturday, October 02, 2010 3:33:13 PMPage 6 © 2006 Mitchell Repair Information Company, LLC.

Removal & Installation
1. Before proceeding, see SERVICE PRECAUTIONS . Disable air bag system. See DISABLING &
ACTIVATING AIR BAG SYSTEM . Remove ignition key. Remove 2 Torx screws from rear of
steering wheel. Lift off air bag module enough to unplug connector from rear of module. Place module
away from work area, with pad facing upward.
2. To install, reverse removal procedure. Tighten Torx screws to specification. See TORQUE
SPECIFICATIONS . Activate air bag system. Perform system operation check to ensure system is
functioning properly. See SYSTEM OPERATION CHECK
.
SIDE AIR BAG UNIT - DRIVER-SIDE & PASSENGER-SIDE
Removal & Installation
1. Before proceeding, see SERVICE PRECAUTIONS . Disable air bag system. See DISABLING &
ACTIVATING AIR BAG SYSTEM . Remove ignition key. Drill out rivets at retaining plate of side air
bag unit. Pull air bag unit out of door. Disconnect connector at driver-side air bag squib. Remove unit
from vehicle. See Fig. 2
.
2. To install, connect connector so that connector audibly clicks when connector engages. Install unit in
door trim panel and rivet using only special rivets (Part No. 003 990 0097). Perform system operation
check to ensure s
ystem is functioning properly. See SYSTEM OPERATION CHECK . which air bag was deployed.

1998 Mercedes-Benz ML320
AIR BAG RESTRAINT SYSTEM 1998 AIR BAG RESTRAINT SYSTEMS Mercedes-Benz
me
Saturday, October 02, 2010 3:33:13 PMPage 7 © 2006 Mitchell Repair Information Company, LLC.

Fig. 2: Removing Side Air Bag Unit
Courtesy of MERCEDES-BENZ OF NORTH AMERICA
SIDE AIR BAG SENSOR - DRIVER-SIDE & PASSENGER-SIDE
Removal & Installation
1. Before proceeding, see SERVICE PRECAUTIONS . Disable air bag system. See DISABLING &
ACTIVATING AIR BAG SYSTEM . Remove ignition key. On SLK 230, remove door sill moulding.
On all models, remove front seat. Fold floor covering in area toward rear. Unclip connector on side bag
sensor. Remove 2 mounting screws. Remove sensor from vehicle.
2. To install, reverse removal procedure. Ensure that arrow on sensor points toward outside. Perform system
operation check to ensure system is functioning properly. See SYSTEM OPERATION CHECK
.

1998 Mercedes-Benz ML320
AIR BAG RESTRAINT SYSTEM 1998 AIR BAG RESTRAINT SYSTEMS Mercedes-Benz
me
Saturday, October 02, 2010 3:33:14 PMPage 9 © 2006 Mitchell Repair Information Company, LLC.

Fig. 3: Removing Side Air Bag Sensor (E Class Shown; Others Are Similar)
Courtesy of MERCEDES-BENZ OF NORTH AMERICA
OCCUPIED SEAT RECOGNITION SENSOR
Removal & Installation
1. Before proceeding, see SERVICE PRECAUTIONS . Disable air bag system. See DISABLING &
ACTIVATING AIR BAG SYSTEM .
2. Remove cover on front seat cushion. Remove ignition key. Unclip connection for occupied seat
recognition sensor on seat connector block. Remove electrical connection lead from seat and pull upward
out of rubberized fiber matting. See Fig. 4
.
3. To install, lay out occupied seat recognition sensor uniformly on rubberized fiber matting. Fabric side
should point upward. Do not kink occupied seat sensor. Reverse removal procedure. Perform system
operation check to ensure s
ystem is functioning properly. See SYSTEM OPERATION CHECK.

1998 Mercedes-Benz ML320
AIR BAG RESTRAINT SYSTEM 1998 AIR BAG RESTRAINT SYSTEMS Mercedes-Benz
me
Saturday, October 02, 2010 3:33:14 PMPage 11 © 2006 Mitchell Repair Information Company, LLC.

Fig. 4: Removing Occupied Seat Recognition Sensor
Courtesy of MERCEDES-BENZ OF NORTH AMERICA
PASSENGER-SIDE AIR BAG MODULE
Removal & Installation (C Class)
1. Before proceeding, see SERVICE PRECAUTIONS . Disable air bag system. See DISABLING &
ACTIVATING AIR BAG SYSTEM. Remove ignition key. Remove instrument panel. Disconnect

1998 Mercedes-Benz ML320
AIR BAG RESTRAINT SYSTEM 1998 AIR BAG RESTRAINT SYSTEMS Mercedes-Benz
me
Saturday, October 02, 2010 3:33:14 PMPage 12 © 2006 Mitchell Repair Information Company, LLC.

passenger-side air bag module squib connector. Remove 4 passenger-side air bag module mounting nuts.
2. To install, reverse removal procedure. Ensure passenger-side air bag module squib connector audibly
clicks when connecting connector. Activate air bag system. Perform system operation check to ensure
system is functioning properly. See SYSTEM OPERATION CHECK
.
Removal & Installation (E Class)
1. Before proceeding, see SERVICE PRECAUTIONS . Disable air bag system. See DISABLING &
ACTIVATING AIR BAG SYSTEM . Remove ignition key. Remove 2 central mounting bolts for
passenger-side air bag module. Lift air bag module enough to unplug connector from rear of module.
Place module away from work area, with pad facing upward.
2. If necessary to replace passenger air bag installation frame, remove 4 frame mounting bolts. Remove
installation frame from vehicle.
3. To install air bag module or installation frame, reverse removal procedure. Activate air bag system.
Perform system operation check to ensure system is functioning properly. See SYSTEM OPERATION
CHECK .
Removal & Installation (S Class)
1. Before proceeding, see SERVICE PRECAUTIONS . Disable air bag system. See DISABLING &
ACTIVATING AIR BAG SYSTEM . Remove ignition key. Open glove box door. Remove 4 clips
securing glove box. Remove glove box compartment. When removing compartment, disconnect glove
box light. Remove glove box door lock striker.
2. Disconnect passenger-side air bag module squib connector. Remove 4 passenger-side air bag module
mounting nuts. Remove passenger-side air bag module through glove box opening. Place module away
from work area with pad facing up.
3. To install, reverse removal procedure. Ensure module squib connector audibly clicks when connecting
connector. Activate air bag system. Perform system operation check to ensure system is functioning
properly. See SYSTEM OPERATION CHECK
.
Removal & Installation (SL Class)
1. Before proceeding, see SERVICE PRECAUTIONS . Disable air bag system. See DISABLING &
ACTIVATING AIR BAG SYSTEM . Remove ignition key. Remove cover below instrument panel.
Remove one bolt in installation slot of center air outlet, and one bolt below right air outlet.
2. Remove air bag panel (3 Phillips screws and 2 hex bolts). Unplug connector at squib of passenger-side air
bag unit. Remove mounting bolts. Pull off and take air bag out of panel opening.
3. To install air bag module, reverse removal procedure. Activate air bag system. Perform system operation
check to ensure system is functioning properly. See SYSTEM OPERATION CHECK
.
Removal & Installation (CLK 320)
1. Before proceeding, see SERVICE PRECAUTIONS . Disable air bag system. See DISABLING &
ACTIVATING AIR BAG SYSTEM . Remove ignition key. Remove instrument panel. Disconnect
passenger-side air bag module connector. Remove 4 screws and passenger-side air bag module.
2. To install air ba
g module, reverse removal procedure. Activate air bag system. Perform system operation

1998 Mercedes-Benz ML320
AIR BAG RESTRAINT SYSTEM 1998 AIR BAG RESTRAINT SYSTEMS Mercedes-Benz
me
Saturday, October 02, 2010 3:33:14 PMPage 13 © 2006 Mitchell Repair Information Company, LLC.

check to ensure system is functioning properly. See SYSTEM OPERATION CHECK .
Removal & Installation (SLK 230)
1. Before proceeding, see SERVICE PRECAUTIONS . Disable air bag system. See DISABLING &
ACTIVATING AIR BAG SYSTEM . Remove ignition key. Remove top section of instrument panel.
Fold vapor barrier toward front to reveal 2 screws. Disconnect passenger-side air bag module connector.
Remove 4 screws and passenger-side air bag module.
2. To install air bag module, reverse removal procedure. Activate air bag system. Perform system operation
check to ensure system is functioning properly. See SYSTEM OPERATION CHECK
.
SYSTEM OPERATION CHECK
SRS warning light indicates air bag and Emergency Tensioning Retractor (ETR) system readiness. Turn
ignition on. SRS warning light will light, and then go out after approximately 4 seconds indicating system is
functioning properly. If SRS warning light does not light, lights up while driving or lights all the time, there is a
system fault. Repair malfunctioning system. See DIAGNOSIS & TESTING
.
SERVICE PRECAUTIONS
Observe following precautions when working with air bag systems:
When working around steering column components and before 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 handling a deployed air bag module. Air bag module may
contain sodium hydroxide deposits which 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 temperatures in excess of 212°F (100°C).
DO NOT expose any SRS component to cleaning agents 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.
DISABLING & ACTIVATING AIR BAG SYSTEM DISABLING SYSTEM
Before proceeding, follow air bag service precautions. See SERVICE PRECAUTIONS
. Turn ignition off.
Disconnect and shield negative battery cable. Remove passenger foot mat. Remove passenger footrest.
Disconnect SRS system connector (X29/9) located at passenger footwell area. See Fig. 5
. System is now
disabled.

1998 Mercedes-Benz ML320
AIR BAG RESTRAINT SYSTEM 1998 AIR BAG RESTRAINT SYSTEMS Mercedes-Benz
me
Saturday, October 02, 2010 3:33:14 PMPage 14 © 2006 Mitchell Repair Information Company, LLC.

Activating System
Turn ignition off. Reconnect SRS syst em connector. Reconnect negative batt ery cable. System is now activated.
Perform SYSTEM OPERATION CHECK
.
Fig. 5: Locating SRS Connectors (Typical)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA
WIRE REPAIR

1998 Mercedes-Benz ML320
AIR BAG RESTRAINT SYSTEM 1998 AIR BAG RESTRAINT SYSTEMS Mercedes-Benz
me
Saturday, October 02, 2010 3:33:14 PMPage 15 © 2006 Mitchell Repair Information Company, LLC.