How to readout DTCs of MCA on-the-desk?

[Go4IT]

Hi guys,

when i tried to read out DTC errors of an MCA which is on my desk (not build in) i found out that it seems not possible?
All request, wheater comming from an readout-software like UCDS, ELM, nor direct OBD-messages send by CANHacker seems to get valid answers.

First i suspected the IPC to somewhat mangle oder renumber the packages, as those requests usually are passed through it, but that seems not the case. A very simple CAN-Message like this (UDS read data by identifier):
727 8 03 22 F1 91 00 00 00 00
Is simply ignored by the unit.

Any idea?

[Syntax]

Should you send some kind of "ignition on" msg which normally comes from IPC?

[Go4IT]

Thanks, i already tried that
285 3 60 00 00 (125 ms period)
but did not make a difference...
unfortunately i never made a CAN recording while doing DTC readout using ELM, ForScan or UCDS. There must be a difference when MCA is on desk or in car, with makes the difference. I really expected the MCA to just answer my requests on the desk... very strange.

[Go4IT]

Oh well, i was wrong, 285 needs to be send periodically and all communication (UDS, OBD) will take place. It seems the unit holds them back until ignition shows up on the CAN. It's also not enough to send it once, it muss be sent periodically all the time of the readout.
Thanks @Syntax for pointing me to this!