I have Ford VCMII which seems best quality and pcb looks like at the picture..
while module programming it says “Battery voltage low ” althought Car battery voltage is good enough ..
in addition to that connecting Booster to the Battery , and
it still gives the same error..
Working solution from one senior VCM2 user:
It is possible you can go back to that ECU” PCM” and look into DataStream of battery voltage? if it is status normal or same as a message during failing flashing….I always have to hook up a battery charger during coding re programming.
Followed with one question ” why wouldn’t your put a supply on anyway ? a battery can show 13v and still be knackered and drain fast”
My experience is:
13V at the battery post doesn’t meant you have 13V at the ECU. If you have a high resistance feed circuit or ground to that ECU for instance! have you check the datatream status, sometimes the status of live data is not true to what actually voltage input is but will guide you where to start the fault at. I always hook up the flash charger because during flashing a cooling fan may turn on or something else will cause battery drop less than 12V…in that MS….unless U have a bench flash station then you don’t need a battery charger to maintain the vehicle’s battery during re flashing.
Credit to MHH menber :