M-Class Model Year 1998/1999 VSS signal

part numbers (USA) (discontinued?)
Q 6 54 0011 CAN-Bus adapter M-Class (163 820 0087)
Q 6 54 0010 CAN-Bus insertion wire harness

part numbers (Germany)
B6 782 2519 CAN-Bus adapter M-Class (163 820 0087)
B6 782 2596 CAN-Bus insertion wire harness
B6 782 2594 Geräteadapter wiring harness

Start by removing the cubicle in the center armrest by taking out the two screws at the bottom, then remove the lid, then the 2 console mount screws. Carefully pop out the center wooden piece prying it out from the rear on either side with a putty knife or similar. It's held in by six snaps and careful with the two in front, they come off easily. Just pry it out starting from the rear sides.

Then remove another pair of screws behind the shifter and lift the cover off the transmission tunnel to gain access to the CAN-bus plug on the small gray box on the rear of the shifter, the transfer case controller labelled Borg Warner. The two other devices one sees on 1999 MLs are the ESP yaw sensor and the ESP lateral acceleration sensor, both labelled ATE, and the airbag controller labelled TRW. Don't unplug the later, it might need to be version coded again at the dealer if you do to reset the SRS light. It's also a good idea not to start the engine until work on the CAN-Bus is completed.

Unplug the CAN-Bus plug on the transfer case controller and insert the harness attached to the green/white cable. The green/white wire goes to the CAN-Bus plug of the new CAN-Bus adapter (the little black box) which I mounted with double sided adhesive tape on the rear of the shift hump.

Finally, route the longish plug from the other wire harness down from the radio cubicle to the CAN adapter's larger plug. By now you have probably started to like the M-Class even more. Very easy to work with, and ample space for cables, and behind the radio cubicle. Then remove the plug from the radio and insert the new harness. The Geräteadapter wire harness has a few other plugs, but these are not needed.

It's also a good opportunity to check the vents to the rear, since the tube leading from the dash to the rear can be loosened and moved up. A little center flap was bent in mine, so the airflow to the center rear bottom could not be adjusted. It was easy to correct and reinstall the vent since it's held in place with just two screws.

2000 Modular COMAND System (MCS 1) (MB Part Number 163 820 21 86)
On the MCS side VSS is on pin 1 on connector A (8 pins) and the reverse or stop lamp signal is on pin 3 on the same connector. With the harnesses mentioned above you don't have to worry about pins. Just plug them in, they are plug and play.   2000 MCS pinouts
2000 model year part numbers
163 820 04 86
163 820 21 86 (latest, replaces ..04 86)

2001-2003 Modular COMAND System (MCS 1) (MB Part Number 163 820 30 86)
VSS is the same pin 1 on connector C1 (16 pins) but the reverse signal is on pin 3 of the second connector C2 (10 pins). But don't worry about it, reverse is not needed and it's plug and play with the above harnesses. The only difference is that 2001 MCSes don't work with the 98-00 factory CD-changer, but a new fiber-optic changer can be installed instead.   2001 MCS pinouts on Ken's site
2001 model year part numbers
163 820 08 86
163 820 13 86
163 820 16 86
163 820 24 86
163 820 30 86 (latest, replaces the others)

CD NAV navigation module 163 820 0989
plugs into the top slot of the MCS 1. It uses 10 navigation software map CDs covering North America. BN 5110

DVD NAV navigation module 163 820 3789 or Q646 0821
plugs into the top slot of the MCS 1 (instead of the CD NAV module). It uses one navigation map software DVD covering North America. BN 5210

CD/DVD NAV installation bulletin (MCS 1)
Installation bulletin (pdf)

MY2004 MCS 1 COMAND
Early model year 2004 MCS with part number 163 820 03 79 have a SVC service button. Later in the year an MCS with SAT button became available as of VIN 489 208 with part number 163 820 05 79.

MY2006+ MCS 2 COMAND
With the new M/R/GL the MOST fiber bus was introduced. Since the AGW audio gateway is integrated with the headunit, speaker connectors are available on the rear.

radios + navigation

"Less is More" Mies van der Rohe

Wolfgang's MB Page