Hi.

I am working with car electronics since a few years. I own some good original programmers. Codex (similar with upa), Xprog and Willem with adapters and other special programmers for special cases, for example key programming..

Especially for chiptuning, i own EVC BDM100 and KESSV2 EU in nice working condition.

I think, the safest way to read an ECU is via BDM with EVC ?! Right ? If i open the ecu and read via BDM, i´ll get all data from ecu and i can always recover completely if there are any problems after remapping. At the moment, i own just adapter EVC 143 for Bosch ECUs.
EDC16 is a widespread ECU and i can always go this way.

Other example. If i read an EDC15 (EDC 15c6 from MB for example) via OBD or via K-Line on the bench and i´ll get problems, what to do ? In adversity, i can open ecu, desolder flash 29F800 and write ori or mod file with willem and flash adapter matched to the bosch part number on the case. Immobilizer is stored in eeprom (95P08 in this case), so it will always works. Right ?

I think, i can go this way with all ecu with flash or eeprom inside. On older ECUs with Eprom (27c256 for example), i always open the ecu, read the eprom, erase with uv light, write mod file and solder it back to the ecu.

Other way to read and write ecu is via bootmode. I never used this way. If i understand correctly, i open the ecu, solder some resistors and the bootmode cable from programmer on special places on pcb and then, i can read and write ?! Right ?

If i am working with an ecu without BDM and without flash or eprom. An ECU with the maps stored in processor. And i can just write and read via OBD, how can i recover if the OBD programmer breaks ?

thx

For first part you are right. For EDC15 is enough to have the eeprom backup.
For boot mode, there are more types. On Me 7.5 for example you put a pin to ground with a resistor, keep it there for 5-10 seconds after powering up ecu, then disconnect pin and read it via OBD port in boot mode. For EDC17 the tool should have his own boot pin that you connect on a pad in ECU and read via boot mode.