Testing ETR Seat Belt Tensioner (500SL)

WARNING: This page is about a different car, the 1993 Mercedes-Benz 500SEL and 1993 Mercedes-Benz 500E. However, it is still accessible from the selected car via links, so may be relevant.

Ensure ignition switch is in OFF position. Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM .
Locate and disconnect SRS Red 10-pin connector (X11/13) under passenger-side footrest panel. See Figure and Fig 1 . Connect Socket Box Tester (124-589-00-21-00) and 10-Pin Test Cable (124-589-35-63-00) to SRS Red 10-pin connector. See Figure .
To determine if SRS/ETR unit or related wiring is faulty, use high impedance DVOM or M-B Multimeter (124-589-19-21-00) to probe socket box tester terminals as per "test connection" column of diagnostic chart. See Fig 2 .
After performing appropriate replacements, activate air bag. Perform system operation check to ensure system is functioning properly. See SYSTEM OPERATION CHECK .

Fig 1: ETR Component Location (500SL)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Fig 2: ETR Diagnostic Test For Seat Belt Tensioner (500SL)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.