The market for Electric Vehicles is on the rise and development is heading at a fast pace. What about diagnostics on EVs?


This article speaks about different diagnostic standards for different kinds of vehicles and throws light on diagnostics for EVs.


There are different protocols/standards in vehicle diagnostics. The main ones accepted and used worldwide are:

BMW i8 plugged in and charging.
  1. SAE J1979 – This standard is mainly used for passenger vehicles like cars, SUVs, 3 wheelers, and 2 wheelers. The standard is developed for both Gasoline and Diesel engines.
  2. SAE J1939 – This is also called as HD OBD, stands for Heavy-Duty OBD. As the name suggests, the standard is used for heavy-duty vehicles like trucks, buses, and off-road vehicles. Primarily the standard was developed for communication between ECUs and later intensely used for heavy-duty OBD.
  3. ISO 27145 – This standard is also called WWH OBD, which stands for World Wide Harmonized OBD. Its applications are majorly in Heavy-Duty Vehicle. (Interested in a scanner that’s generic to the above 3 OBD standards? Try Silver Scan-Tool – A Plug and Scan generic OBD tool)
  4. UDS – UDS stands for Unified Diagnostic services and follows the document SAE J14229. The above 3 standards are accepted worldwide for certification and homologation by different authorities. UDS enables OEMs or suppliers to set up their own diagnostics which is useful for testing at different levels of development and also after-sales & maintenance. (Interested in an all in one diagnostic tool? Try DiagRA D, read about it, and get to know how it makes testing activities easier)

Now let’s talk a bit about EVs (Electric Vehicles). Until now, there are no OBD standards specific for EVs. For conventional engines, the standards and protocols are matured, accepted, and used worldwide. However, for EVs, none of the authorities or organizations have come up with any standard. The same standards may be used with EVs with changes like Motor speed instead of Engine speed, Battery status, etc. But it needs to be seen how it all turns out to be.

Until then the EV manufacturers and suppliers can use UDS for their own diagnostic applications. It is also seen that some of the EV OEMs are already using UDS.