T4 TDI Automatic Control Unit Error 01316 Brake Communication

Hello,
I have a VW T4 bus with a engine and an automatic transmission.

In the control unit of the automatic transmission, error 01316 - Brake Control Unit 49-10 - No Communication - Sporadically is always set after engine start and pressing the brake pedal (see log).

In the measurement block 125, Motor 1, ABS l. 0 and switch box 0 are displayed, while in the instrument panel, Motor 1 and Gear 1 are displayed, and the brake field is empty.

In normalem Betrieb hat dies keine Auswirkungen. Das Getriebe schaltet einwandfrei, der Schieber wird durch den Bremspedal freigegeben, und das Getriebe wechselt beim Anhalten automatisch in den Leerlauf.

What could it be?

Best regards, Till

Hello Till,

I would proceed as follows:
- Does the brake pedal switch operate smoothly? Is the brake pressure in the ABS/ESP system plausible?
- Battery ok? (possibly excessive voltage drops during the starting process)
- Software/Hardware fault in the ABS/ESP or automatic transmission control unit? Are there similar known errors on the web, and what are the software versions/part numbers of the involved control units?

Best regards, Rainer