Removal and installation of airbag and seat belt tensioner control unit - ra91001400622x(0622)

WARNING: This page does not describe the selected car, but rather 42 other vehicles, including the 1999 Mercedes-Benz S600, 1999 Mercedes-Benz S500, 1999 Mercedes-Benz S420, 1999 Mercedes-Benz S320, and 1999 Mercedes-Benz CL600. However, it is still accessible from the selected car via links, so may be relevant.

Model 140

Operation No. of Operation Texts and Work Units, Standard Texts and Flat Rates 91-1911

Fig 1: Identifying Airbag And Seat Belt Tensioner Control Device Components

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

REMOVAL

Ignition key	turn to "0" position.
Negative battery terminal	unclamp and mask.
Radio (1)	remove.
Ashtray housing	remove.
Screw on wooden surround of ashtray	loosen.
Wooden surround (3)	remove in upward direction.
SW4 screws (4) on cover (5)	unscrew.
Cover (5)	push to the rear and remove in upward direction (arrow).
Plug connectors	detach on switches.
Screws (6, 7) on cover (8)	unscrew.
Cover (8)	remove in direction of arrow.
Plug connectors on switches	detach.
Plug connector on airbag and/or seat belt tensioner control device (N2/2 and/or N2/1)	detach.
Intorx screws (2 pcs)	unscrew with special tool.
Control device (N2/2)	remove.

Installation Note

The arrow on the control device must point in the direction of travel.

Install in reverse sequence.

The "SRS" warning light must go out after approx. 4 secs.

Special Tools

Fig 2: Identifying Special Tools (126 589 00 10 00 46)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Fig 3: Identifying Special Tools (124 589 19 21 00 07 83)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Fig 4: Identifying Special Tools (140 589 14 63 00 54)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

STANDARD TOOLS

Ratchet (1/4")	Article No. 415	e.g. Eduard Wille GmbH
Connecting piece	Article No. 412	Postfach 12 01 03 D-5600 Wuppertal 12

Testing after Replacing the Control Device

Fig 5: Testing Control Device

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

There is an integrated diagnosis program in the control device which checks the control device and the electrical airbag system components. If it detects a fault, the warning light (A1e15) does not go out after 4 secs.

The faults detected are stored and can be called up as an impulse signal via the warning light (A1e15) and/or digitally via an impulse counter. For testing see Diagnosis Manual, Bodywork Volume 2.

Notes on Impulse Signal

The numbers 1 -10 appear on the display field of the impulse counter.

The number 1 means that no faults in the system are stored. All further numbers are allocated to a certain circle of faults. If there are several faults in the system, the fault with the lowest impulse number is read out first.

If the U-Batt. light diode appears after connection , the impulse counters and power supply for the impulse counters are in order.
If the first number appears again during testing after at least two or more impulse outputs (numbers), all faults are read out.

Diagnosis impulse display

Connect impulse counters on the basis of the connection diagram.
NOTE: U-Batt light diode in display field must light up.
Switch on ignition.
Press starting button between 2 and 4 secs.
Display 1, no fault in system.

If another number appears, remove fault according to Diagnosis Manual, Bodywork Volume 2.