MSS54 - checkum calculation can't it be turned off?

[Tomba]

Hello members,

I am currently preparing 2 MSS54 ECU to be used with an emulator (OLS300) and would like to know if there is a way to turn off checksum calculations? I use 2 ECUs as 2 memories need to be emulated. First Master (ignition) and later Slave (injection/vanos). Currently when I change a bit the EML light goes on and limp mode is activated. My main goal is to fine tune new Schrick camshafts for optimum cylinder charge. On stock tables 10-15% air charge is decreased. When loading CSL VANOS tables an improvement can be observed over stock but I like to squeeze the best out of it. I know from memory that on the original "Comprehensive MSS54 thread" someone mentioned to set one of the cfg.xxx variables to a specific value to turn off checksum calculation. But I simply don't know which. Do some of you remember or can guide me in a direction?

Best regards,
Tomba

[MpowerE36]

Hello members,

I am currently preparing 2 MSS54 ECU to be used with an emulator (OLS300) and would like to know if there is a way to turn off checksum calculations? I use 2 ECUs as 2 memories need to be emulated. First Master (ignition) and later Slave (injection/vanos). Currently when I change a bit the EML light goes on and limp mode is activated. My main goal is to fine tune new Schrick camshafts for optimum cylinder charge. On stock tables 10-15% air charge is decreased. When loading CSL VANOS tables an improvement can be observed over stock but I like to squeeze the best out of it. I know from memory that on the original "Comprehensive MSS54 thread" someone mentioned to set one of the cfg.xxx variables to a specific value to turn off checksum calculation. But I simply don't know which. Do some of you remember or can guide me in a direction?

Best regards,
Tomba

Try to modify 0xF (cfg_s.status) and 0x400F (or 0x800F for HP) (cfg_m.status) from 132 to 0

[S54B32]

Anyone succeed on mss54(hp) ecu with a emulator? At least on master side? I tried, but never get it 100% to work.

[Tomba]

yes, OLS300
worked fine without checksum plug-in

[S54B32]

Any special modification, beside checksum off? (Cfg status)
Did you see any "abnormal" behavior, because ecu can not write to the emulator, but it wants to for some adaptions (like idle etc).

[Tomba]

only used it on dyno, during that no problems occured.

[S54B32]

Do you still have you base (or any file) from this?

I have a hard time to get this running, sadly I didn't found a genuine OLS300, so I had to buy the only emulator that was available from a company called CobraRtp. I'm a bit unhappy because connection is not so stable and it doesn't work out of the box, many tests and fault search necessary to get the ecu to boot. Also connection to tuner pro is a hit and miss. But from ms43 community I heard only good things about this device..

Big downside on emulators with mss54 is, that the ecu always try to write something (like faults or adaptions for idle etc) to the eeprom which is not possible due one way write access of the emulators.
Currently I have deleted chk's and can boot the ecu, but it does not work like expected, faults are always present (not possible to delete, because it seems they are stored in the eeproms), only limp mode and so on..

[Tomba]

Let me check this for you during the week.