What I think could happen here is that the DigiTrax system might be set to a different (earlier) DCC setting (e.G 27 speed steps?)
Could also be that the decoder might need to be set to DCC and not Selectrix...but since I don't have the manual on this 222202, I couldn't tell.
If you have access to an Intellibox, you might be able to figure this out easily, as you can switch between modes: Marklin-new or -old, DCC, Selectrix etc.
Hope this helps

Thanks Fredrik,

I saw in the users manual that it has been set to address 3 from the fabric.
It also says something about a Central Control 2000 (but I don't know what that means) that has be set for DCC operation.
No-one has touched this train before I purchased it and my friend nor I didn't change anything either.
So I am pretty certain that the address is "3".

I copy a part here from that users manual :

Function
• Possible operating systems: NEM direct current (± 12 volts DC), DCC System (NMRA standard).
• Selectrix operation: Central Control 2000 must be set for DCC operation for this train.
• Different controllable light and sound functions when the model is operated with DCC.
• Headlights change over with the direction of travel and vary in brightness according to the voltage
present in the track, when the unit is operated with direct current.
• Only available with DCC operation: Different parameters can be set (address, maximum speed,
acceleration delay, braking delay, volume). Address set at the factory: 03.
• Fitted multi-pole special coupling between the carriages.
This coupling is only used for this model type and is not compatible with other coupling systems.

Thanks again Fredrik, if the decoder would be faulty I think it almost certainly wouldn't have run on the analogue track either. On the analogue track only ONE of the 2 loco's was able to move on its own. The other loco was dead on its own but was running when I coupled it to the other one (with the cars in between them). My friend won't be home for another week so I still have to wait. He is a good expert and I am sure he should be able to try out a few of your suggestions. Will of course let him know about your suggestions and also about the speedsettings from Jacques.
Best Regards,
Jan

You should try first to reset decoder.
Are you sure that decoder in this Trix model stand at adress 3...?

I would expect that the motor unit A functions on it's own, at least in one direction. When switching to the other direction, a relay is tripped, allowing the trainset to collect power from the motor unit that is at the front of the train. This means that the two motor units have to be connected for the trainset to operate properly in both directions, both in analog and in digital operation. I am not a DCC expert, but I am guessing that somewhere, the decoder has to be switched from Trix (Selectric) to DCC in order for it to operate on that system. This setting would not affect the analog operation of the trainset at all.
The information for switching it to the appropriate system should be available in the instructions of the trainset and/or of the decoder.

Regards

Mike C

There is a plug (see page 41 of the manual). But train should work in both positions AFAIK.

This decoder doesn't support Selectrix, that's why Central Control 2000 must be set to DCC operation.

Manual says: never use one locomotive alone.
14 speed steps are default, 28 or 126 speed steps are automatically detected (so that should be no problem). Default address 3.

Writing 8 to CV 8 will reset the decoder to the factory settings.

Manual can be found here:

(copy URL to address field)

The train should operate with both locomotives properly connected (check the plugs for bent pins). The address should be checked or re-programmed or reset the decoder.