I tried everything.checked wiring.no good..so I used another tool using the same connection and it read the ECU no problem...these problems have to be sorted quickly as nobody can depend on this tool .I want a answer why it's not reading and not excuses anymore.

I had the same problem... not with PCR2.1, but with a DENSO SH01.
Kess and pcmflash can connect with it without problem, hexprog not even touch it. Not factory mode or boot mode.

I'm afraid to open a SID310 from Mercedes A180, because other tools, like SMOK needs to extract password in OBD mode, then use the password in boot mode. I doubt hexprog can extract and decrypt password only in boot mode.

For the price that hexprog costs, this issues must not exist... not in this kind of ecus.
In you case, pcr2.1 is an old known ecu... almost every tool can communicate with it without problems. Personally, I use pcmflash for pcr2.1.

I hope hexprog team can solve your problem.

Regards
Pedro Dias

For pcr2.1 support need to check your device here, as we have tested ourself with pcr2.1 and it is working here. so for further test we request the device to send to us. for the SH01 please contact support to check your issue. Also, check simos pcr2.1 is working with the tool and inform us. SID 310 some ecu versions we dont support , as it is unsupported one and all other sid 310 can be done using hexprog well.