I'm learning about OBDII, and I'm wondering whether it is valid on EV's too.

According to Wikipedia's PIDs article, the Service 01 PID 51 (or Fuel Type) has a value 8 that means that the fuel type of the vehicle is Electric.

However, it seems that the corresponding regulation (ISO-15031) is only about "emission relevant" information? From what I can deduce, OBD-II is a general reference for all type of vehicles and ISO-15031 is only a subset of OBD-II that regulates PIDs on emissions. Is that correct? I also read on the same Wikipedia page that there are 10 services, but it seems that only 3 of them are documented (1,2,9). I'd like to know whether there is an official document on the OBD-II standard.

My question is as follows: Is the word "emission-related" (that one can found in various services) only an historical trace from the birth of OBD-II standard? (To what extent does the standard apply to EV's?)

  • @SteveMatthews no mechanical problems, I'm learning what is OBD-II and if it is valid also for EV.
    – Nameless
    Nov 27, 2018 at 14:30
  • 1
    OBD II is the On Board Diagnostics standard which was mandatory for all petrol vehicles from 1997 and diesel from around 2002ish. It allows a standard interface to be used to diagnose onboard systems, irrespective of manufacturer. I believe the initial motivation for bringing it into law was to make advanced emissions testing easier. It is my understanding that the likes of Tesla implement the absolute minimum legally required OBD functions and nothing more. Nov 27, 2018 at 14:49
  • @SteveMatthews So you think that "emission-relevant" is an historical trace too, right?
    – Nameless
    Nov 27, 2018 at 16:03
  • 1
    Don't confuse base OBD II protocol with CAN-BUS, which may be more what you're hoping to understand. Like I say though, many EV's implement the absolute bare minimum OBD functionality only so they can pass registration / inspection. Nov 27, 2018 at 16:41
  • No, I'm not confusing OBD with CAN Bus. I know that CAN bus is a physical bus, and it is not related to OBD standard (PIDs, DTCs, Connector). Then, on CAN bus, that is used for communications, an OBD-II communication can use -for example- CAN Protocol, or UDS protocol, and so on... So, my doubt is the same: I can't find an official document for OBD-II standardization and in addition I think also that OBD-II is nowadays not only about thermical engine vehicles.
    – Nameless
    Nov 27, 2018 at 19:29

1 Answer 1


The obd 2 port has its roots in the old obd1 systems found in cars the years leading up to the standard being created in 1996/1997 and was only intended to alert the driver that the computer detected elevated emmisions out of the tailpipe indicating that repairs were needed somewhere. OBD 2 was forced upon manufacturers by california in 1996 to simply create a uniform standard with which to get the information given by the computer(and so they can test cars easier for mandated emmissions tests) Therefore electric vehicles which do not have any computer or sensors to control emmisions nor are subject to mandatory emmissions testing have no need for such a port to connect to. As vehicles' computers and sensors evolved over the years to be faster and record more data the obd port became the obvious place to interface and read said data but this was just intended to find and fix whatever the problem creating the elevated emmissions was. All codes and data readable on the obd port have this goal in mind and serve no purpose of diagnosing other faults present in the engine or otherwise. Once again having no purpose on an electric vehicle not containing emmissions equipment

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .