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OBD-II is ancient

It predates the Porsche 911 GT1, Windows 95 and implementation of the Schengen Agreement.


I would have thought that SAE would be working to add more diagnostic coverage for features that are virtually essential to most passenger vehicles today, such as ABS, airbags and traction control, but can't seem to find anything.

There is OBD-III, but my limited research suggests that it seems to do nothing to enhance the diagnostic capabilities that are present in OBD-II today.

So are there plans afoot for something that can improve the diagnostic standards across the industry?

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    It seems to me OBD-III was going to be something mandated by the government here in the US but got tons of backlash. The backlash was because they wanted to be able to see into people's cars as they were going down the road to understand how a vehicle was running and how much pollution it was emitting etc. (I say see in the generic sense.) With it they could also see how fast an individual was going and many other things which would have been considered an invasion or privacy here in the US. Just my take on it though. Glad they haven't gone through with it; hope they never do. – Pᴀᴜʟsᴛᴇʀ2 Jan 20 '16 at 0:26
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Your question need answered with another question. What diagnostic capability do you want?

While the generic side of OBD-II leaves something to be desired and has been stagnant since it's inception, the manufacturer specific side of OBD has made tremendous leaps and bounds from where it started in 1996.

  • My old 1996 Nissan Sentra had about 2 dozen pids. The last time I connected to a Mazda CX9 there were over 100. In fact there were so many that the scan tool (IDS) could not display them all at the same time.
  • The speed of the computers has increased a lot. The rate at which it catches sensor glitches is now astounding. With early OBD lazy sensors were often missed. Today there are usually several codes for the behavior of a sensor beyond sensor high and sensor low.
  • When OBD came out they could barely run the misfire monitor while running everything else. You could throw away a spark plug wire and drive the car for days before it throws a code. Now I've caught a single misfire event in Mode 5 data. The early GM 3800 had a very basic crank sensor. The current GM vehicles have up to a x54 crank sensor giving amazing resolution.
  • Freeze frame data now have more pids stored and can store multiple events.
  • Communication with the scan tool have improved. The speed of class 2 is like a snail when compared with CAN. There were instances where plugging in to a separate connector was necessary when accessing other systems in the car beyond the engine. Now every module is accessible through the network.

These are just a few examples of how while it seems stagnant the diagnostic capabilities have improved.

  • Wrt diagnostic capabilities, I'd say that several things could be improved. I'd like to be able to distinguish between HP and LP fuel rails on gasoline direct injection vehicles, for instance. The latency is horrible (my understanding is that this is because you can't poll a dedicated PID to the exclusion of others). And leaning on manufacturer-defined PID's for further information is hardly in keeping with the spirit of a diagnostic "standard" (I'm not saying that manufacturer-defined PID's should be totally absent, but I feel the industry is leaning too much on them). You have my +1 btw – Zaid Jan 20 '16 at 6:53
  • You can't poll a dedicated PID? I'm pretty sure you can, just not all software supports it. Latency is high because you are probably using an old protocol. OBD2 has changed a lot since the 80s, modern systems use CAN communication which is pretty quick. – I have no idea what I'm doing Jan 20 '16 at 9:48
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    @Zaid Most manufacturers have a pressure sensor have a pressure sensor in the HP fuel rail. They use that sensor to control the pressure in the rail. As IhavenoideawhatI'mdoing suggests you may be using an older protocol or it may be a short coming of the scan tool itself. CAN is very speedy. As far as manufacturer PIDs go every time they add a sensor they add a PID to cover it. – vini_i Jan 20 '16 at 12:17
  • @vini_i What do you use for your OBDII tool? – DucatiKiller Jan 21 '16 at 0:17
  • @DucatiKiller At my last job at a garage I used; IDS - Ford Lincoln Mercury Mazda, Tech 2 - anything GM, MasterTech - older Honda, Solus - everything else. I am no longer in the business. For personal use i have a Matco MD60, I believe it is a rebadged Innova. – vini_i Jan 21 '16 at 0:25

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