Which flavour of OBD-2 signal on 96 850 wagon?

Py · Post by Py » 14 Jun 2008, 12:29

Hello,

Since this morning, I'm the happy owner of a 1996 850 wagon, with the 2.5i 10v non-turbo engine. It is a Belgian car, bought from first owner, an old Doctor.

The car as a low 105.000 km on the clock, and I got a real bargain on it because it suffers from the typical ABS problem, and Volvo asks for about 1500

Py · Post by Py » 19 Jun 2008, 06:32

Well, in the meantime, I've taken a second look at the thing, and I'm quite puzzled.

As the populated pins on the car's connector are often a hint to find out which protocol is used, I had a second look.

On my car, and in respect to the above schematic numbering, pins, 1 - 3 - 4 - 5 - 6 - 7 - 13 - 16 are populated.

But looking at the various informations I found online about OBD2 (eg http://www.auterraweb.com/obdiipinout.html), this pinout doesn't match any of the common signalling protocols.

On the other hand, I checked my scanner pinout, and its pins 5 - 7 - 15 - 16 are populated. As it is a working (verified on a Peugeot) ISO-only scanner, it seems perfectly sound.

So, what for a strange OBD-2 connector do I have in the car? In fact, I'm not sure if the car is a 96' or a 97'. Was sold as a 96', but user manual is from a 97' (and it is the original), and airbags revision was due in 2007. Maybe there is a way to figure out looking at the VIN, or does it have to be checked against a DB (anyone here can do that)?

Anyway, from what I read, vehicles from 96' or later should all be OBD-2 compliant (and supposedly not much different)... Really strange, any opinions?

Post by **MadeInJapan** » 19 Jun 2008, 07:13

Just for kicks have you looked under your hood to see if you have the Volvo diagnostic boxes next to the windshield wiper tank? If you do, I would use that rather than trying to use a first generation OBD port as Volvo's diagnostic boxes will tell you more specific information about your car's issues. Also, I read somewhere that the early OBD system for Canadian cars was different than for those headed to the U.S. but I haven't been able to confirm that. Apparently the first rendition of OBD in the U.S. (at least what came in Volvo's) was ISO-9141-2. Later versions ('98 or '99 and newer) used a different, ISO 14230-4 OBDII standard. Some refer to these standards as OBD-I and OBD-II. Anyway, hopefully these ISO numbers will help you search out more specifically why you aren't able to retrieve your codes with the scanner you now possess. My suspicion is that you have the first version of OBD in your car which is the ISO-9141-2 and your scanner is for the later version. I should add that Volvo uses a couple of specific pins as well (don't recall which ones) that only give information to the VST (Volvo Scan Tool) and are Volvo specific so really the extra pin signals are not something we as Volvo non-professionals need to worry about to much. That information is not that helpful in diagnostics anyway although it would be nice to access in order to reset SRS lights and read the ECC (electronic climate control) codes if your car is so equiped.

Good luck and let us know how things shape up.

Py · Post by Py » 19 Jun 2008, 07:45

Ok, I'll have a look this evening for those Volvo diagnostic boxes (I'm at work atm). But I doubt they're fitted to my car.

In fact, the scanner I own is compatible with both ISO 9141-2 and ISO 14230-4. Double checking the information I point to in above post, and crossing it with other sources, I figured out that pin 15 (L-line for ISO protocols) is optional. So at least it seems that with pins 5 - 7 - 16 populated, the car looks like an ISO-compliant device. A little bit less strange than my previous conclusion

As I said in the first post, this is a European version (I bought it from it's first owner a few days ago, and am located in Belgium). And for what it's worth, the connector cover (you know, the one with the slots for some coins) has "OBD-II" on it.

But I'm still unsure if it is a 96' or 97' model year car. Anyone with a way to definitely confirm that according to the VIN, or by looking at some hidden place? Most of the car parts are stamped around September or October 1996.

Anyway, I'll have a look for those diagnostic boxes and let you know!

Py · Post by Py » 19 Jun 2008, 08:13

Another bit of information:

http://www.blafusel.de/misc/obd2_scanned.php#1030

So it looks like the situation is not the same for European and US vehicles... Any European around with OBD experience on his car?

Post by **MadeInJapan** » 19 Jun 2008, 08:28

I see what you mean but have no idea. It appears that ELM based software won't work...are you using a laptop & software to scan the OBD port?

Anyway, information I can offer you is that in Europe, Volvo's are marked one year ahead of the U.S....so a '92 in Europe is a '93 model in the U.S....etc. May not be much help but this could be why you have a '97 owner's manual with a '96 Euro car.

Py · Post by Py » 19 Jun 2008, 08:50

I'm using a laptop connected to an electronic circuit based on an ELM323 (ELM's are dedicated chips). The software tool I used is scantool.net.

I was under the impression that vehicles with the diagnostic boxes were using a Volvo-specific protocol (for scanner-based access/configuration), and that starting around 96', they moved to standard-compliant OBD-2 diagnostics, and the diagnostic boxes were dropped as part of the move.

In my understanding, there is no place/gap on the timeline where cars have been produced without diagnostic boxes AND with only volvo-specific diagnostic protocol (as this would basically mean that on such a car there is no way to access any diagnostic data without the expensive Volvo specific diagnostic tool).

Post by **MadeInJapan** » 19 Jun 2008, 11:07

You'd be surprised...a number of our members have (in their mid-90's) 850 found both the diagnostic boxes and an OBD port in their cars. Just thought I should let you know...worth checking. And to be honest....the diagnostic boxes under the hood will give you much more accurate/Volvo specific data than what you or I can obtain from the OBD with or without a software/laptop setup.

Good luck!

Py · Post by Py » 19 Jun 2008, 12:00

Interesting! I just came home, went to the Volvo first thing, and there are no diagnostic boxes under the hood. Nothing on the right of the filling pipe for the washer fluid tank, except the moldings to mount them on the plastic casing behind.

So, I think I ought to find a solution to read stuff off the OBD connector, or I'm SOL regarding diagnostic codes...

Anyway, your statement regarding the presence of both the diagnostic boxes and an OBD connector does not invalidate what I said previously. To summarize, I wanted to say that my understanding was that on any 850, at least one "open" way of reading diagnostic codes (diag. boxes or standard (eg not Volvo specific) ISO OBD-2) was always present. If both are, it's even better... Not my case!

Post by **MadeInJapan** » 19 Jun 2008, 12:20

See if you can borrow a code reader (non-software type) and see if you're able to connect with the ECU. I agree with you, unless you have a short or a disconnect you should be able to read the codes someway. Volvo never made a car without some sort of diagnostic ability.