Detection of short circuit on CAN bus with TLE9255W

[SHan]

Hello,

 It is described in the specification for TLE9255W that CANH and CANL pins are protected from the short circuit to GND or supply voltages with a current limiting circuit.  However, apart from that safety mechanism, there's no description for how the TLE9255 detects these electrical faults on CAN bus 
 Is there any way that I can detect this type of faults with TLE9255?

Thanks for your answer, in advance!

[Di_W · Accepted solution]

Hi SHan,

The short circuit protection is a machanism, not a detection and there is no status register for it. There are multiples types of faults: CANH and CANL shorted to GND, VBAT, or to each other. Each have a different behavior. By looking at the power consumption, the duty cycle of TxD low, and the success or failure of communications can indicate the type of fault. Please note the communication with likely continue as normal even with CANL shorted to GND, so using the communication on RXD won't be an indication to the controller, at least not reliably.