Adding insult to injury, the standard OBD2 protocol provides parameters like engine rpm etc., and thus with the usual ELM323 OBD-bluetooth adapters you can get for cheap on aliexpress and the usual bunch of phone apps you don't get to see the error codes, or what the actually mean. Those error codes are manufacturer specific and the manufacturers don't tell the world what they mean, preferring you to go to their brand shop in order to read and decode them.
For VAG (Volkswagen, Audi etc.) there's a software shops can use called VAG-COM that sells officially for a few $thousands, but you can get it very cheap from aliexpress (I'm quite sure it's pirated, so..). I guess something similar exists for other brands too.
For VAG (Volkswagen, Audi etc.) there's a software shops can use called VAG-COM that sells officially for a few $thousands, but you can get it very cheap from aliexpress (I'm quite sure it's pirated, so..). I guess something similar exists for other brands too.