History of GenBoard/Firmware/BootLoaderLoopback
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2017-06-18 07:25:10 . . . . catv-80-98-142-196.catv.broadband.hu [follow steps; check DSUB9/pin5 ground]
2016-09-14 03:21:44 . . . . catv-80-98-142-196.catv.broadband.hu [minor cleanup; highlighted bootloader mode => "Stay"]
2016-09-14 03:18:09 . . . . catv-80-98-142-196.catv.broadband.hu [minor cleanup; highlighted bootloader mode => "Stay"]
2008-08-23 04:18:33 . . . . 3e70d19f.adsl.enternet.hu [loopback hints]


Changes by last author:

Changed:
In special, rare cases, eg. when firmware upload is interrupted or unable to communicate with firmware for some other reason, use RS232 loopback to force ECU stay in bootloader mode after bootup:
In special, rare cases, eg. when firmware upload is interrupted or unable to communicate with firmware for some other reason,

one usually sees VemsTune Boot Mode Detected => Stay

* That is promising.

** Just skip the first few steps and continue with Stay step below, very easy !

** However, first make some measurements and review/verify basic things.

*** Is DSUB9/pin5 really connected to ECU EC36/26 GND ? (EC18/17 is NOT always GND, especially if dual WBO2 or 2nd WBO2 heater FET was requested, so verify connectivity to EC36/26, or the the relevant motronic GND pin). Are GenBoard/Manual/GroundConnections

good ?

*** Is the (driver+USB/) serial port reliable in both directions ? Eg. not dropping leading bytes after some silence ? The firmware upload also involves error detection and resend, but ECU => PC(VT) runtime data tolerates high error rates (very high error rates in the PC(VT) => ECU direction might go unnoticed during daily use, that results PC(VT) => ECU fw upload error.

Otherwise (to get to the "Boot Mode Detected"), use RS232 loopback to force ECU stay in bootloader mode after bootup:

Changed:
** Do not forget to disconnect (or just exit the TerminalProgram) to free up the serial port.

* run the PC side firmware upload application

** [vemstune] Firmware / Firmware verify (or upload)

** or edit upload_firmware.bat to set COM port. (This runs megaloader. Found in MegaTune distribution)

* you might need to reboot

** Disconnect from TerminalProgram (or exit) to free up the serial port.

* run VemsTune to upload firmware from PC (the above steps not needed if you see "Boot Mode Detected"

** Boot Mode Detected => Stay ; Tools / Firmware / Firmware upload (VT might recommend the multifunction "upgrade wizard", but the old upload is best in this case: saving old vemscfg would likely not succeed anyway if you're doing this)

** OBSOLETE: or edit upload_firmware.bat to set COM port. (This runs megaloader. Found in MegaTune distribution)

* you might need to reboot (turn +12V supply OFF and ON)

Added:
If executing the above procedure very precisely at least twice, and still not getting "Boot Mode Detected", the boot loader might be damaged. That is extremely rare (but not impossible), and if happens, usually experienced soon after some external circumstance (eg. welding, or disconnecting ECU while powered up; injectors or other inductive solenoid loads without flyback path, etc...)