NOTE: This may not be applicable to a 1995 thru 2001. Try running the windows up and down to resync the system.

Mercedes Soft Top Controller Reset Procedure. R129 1990 thru 1994.

Locate the diagnostic connector: Under the plastic cover near the hood-up switch on
the passenger side of vehicle near the strut mount.

To recover codes for the soft top controller:

Connect a normally open (N.O. S.P.) switch between pin 1 and pin 10. A simple push button switch with leads or a short jumper lead will also work OK.

Short (close switch) 2 to 4 seconds to read error codes.
The lamp in red top switch ( in the console ) will flash out a number of pulses.
Count the pulses and see the chart.

Short (close switch) 6 to 8 seconds to erase error code.

There may be multiple codes stored.

Some codes may require reading / resetting twice before they will erase.

The codes that will suspend operation of a soft top on the R129 are 21, 22, 26, and 30.

A code of "1" indicates no faults and no hard top in place, while a code of "20" indicates no faults and the hard top is assumed to be on the car.

3.= Limit switch, right locked ,soft top storage compartment cover.
4 = left compartment cover closed switch
5 = right compartment cover closed switch
6.= left front latch switch.

10.= left rear latch switch.
11.= right front latch switch.

16 = roll bar retracted switch.
17 = Left window failed to lower (limit switch open).
18.= Right window failed to lower (limit switch open).

20 = Hard top installed, no faults.

23 = roll bar control unit not functioning.

25.= contradicting inputs.

27 = insufficient voltage.
28.= Speedometer signal is missing.
29.= Wheel speed from ABS control module missing.
30 = Top operation disabled (due to #29).

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