TJA1041AT Bus recovery Failed？

[IvyGuo]

The CAN bus consistently outputs a dominant signal, occupying the bus and preventing other nodes on the bus from sending or receiving data. At this point, CANH is at 3.7V, CANL is at 1.2V, and the ERRN pin is at a low level, indicating a continuous error. Following the instructions in the chip manual, we forcefully reset the CAN transceiver, set STB to 1, set EN to a low level to disable transceiver output. At this moment, ERRN is at a high level, resolving the error. After a period of time, we re-enable the transceiver, set EN to a high level, allowing the transceiver to output, and ERRN is also at a high level. However, CANH remains at 3.7V, CANL at 1.2V, and the error persists without recovery.

I'd like to confirm two points:

1. What are the common reasons for the continuous errors on the CAN bus and the inability to recover?
2. Does TJA1041 have a recovery mechanism? Why, in the case of a certain number of bus errors, does TJA1041 not trigger bus-off but instead continuously occupy the bus, preventing other nodes on the bus from sending or receiving data?

[TomasVaverka · Accepted solution]

Hello Ivy,

Please refer to the AN00094, Chapter 10 - Local failure diagnostics. There should be available all relevant information related to your questions. I do not have any other ANs or other documents for this pretty old CAN transceiver. 

BR, Tomas