OBDII vs Tech II

[trollbooster]

This has probably been asked several times before, so please accept my apologies if I ask again. Did a search couldn't find an answer!

What is the difference between OBD II and Tech II? I appreciate that Tech II is a SAAB tool and OBD is an international protocol for all vehicles.

My understanding is that Tech II is interactive, i.e. settings can be changed with it, whereas OBD II is just a passive diagnostic that will tell you what is wrong the car.

My dilemma is that the CEL on the 9-5 won't go out, despite have disconnected the battery overnight twice. My local garage want to charge me ½ hr labour (~ £55 ) to run it on Tech II to reset it and presumably diagnose any errors, whereas I can buy an OBDII tool for just under twice that. (which apparently resets the CEL anyway.

I am, somewhat understandably, reluctant to splash out £4k on a Tech II tool

Thanks.

[billj]

[ QUOTE ]
My understanding is that Tech II is interactive, i.e. settings can be changed with it, whereas OBD II is just a passive diagnostic that will tell you what is wrong the car.

[/ QUOTE ]
You can make some changes with OBDII. Certainly, you can clear the fault codes. But it is largely passive, the "D" standing for "Diagnostics".

The real difference is that OBDII defines a standard set of commands that all OBDII-compliant cars must meet. Tech II will cover these plus many, many GM-specific commands, using the same communication protocol as OBDII, I believe.

You should be able to use an OBDII tool to clear the fault codes as I have on my 9000 Aero.

£55 for half an hour sounds a lot, especially oop-Nawth. I'd hope my specialist would do it for a lot less than that and expect they probably wouldn't charge at all. There's always the chance they might get some money out of it if they fix a fault that causes the light.

[trollbooster]

Thanks Bill,
The last Indie up here I asked about Tech II said he could do it but admitted that he took the car to the local dealer for them to do it.

[billj]

That'll be why it took half an hour, then
And half an hour of two garages' time could easily come to £55 ...

[trollbooster]

[ QUOTE ]
That'll be why it took half an hour, then
And half an hour of two garages' time could easily come to £55 ...

[/ QUOTE ]

No, I didn't bother with this indie, I took the car out and gave it a good thrashing and that cleared everything up. This was a 9k a while back.

The £55 refers to just the main dealers time from a quote this morning......

[murphwiz]

OBD2 is a protocol aggreed on by all motor makers to allow basic diagnostics to be carried out, this only became law within the EU around 2001.

Tech2 is a GM specific diagnostics and programming tool, all makers have thier own, different diagnostics tool.

Dependant on model year of 9-5 it may not be obd2 compliant anyway.
All 9-5 Aeros were, and post model year 2001's.

[trollbooster]

Thanks Leon, I think you might have just saved me £100 (well £45 as I'll have to get it Tech II'd at the dealers (it's a 2000 MY)

Cheers

Robert

[markcanderson]

All cars sold in the USA since 1st Jan 1996 have to use OBD as their interface standard. It was introduced, as electronics became more important in engine and gearbox control, to allow home-mechanics and small business garages to look after cars and stop dealer franchises being the only place that could service cars.

Most manufacturers now use it across their vehicles. Saab unfortunately continue to use a proprietary interface standard (Tech II) which costs a bomb for the reading equipment and software licenses for all their non-usa vehicles.

More info about OBD2 here. http://www.obdii.com/background.html


But, many products have appeared for the home enthusiast to add as part of the car's toolkit in the garage.

As you can see from here :

http://www.ecutek.com/products/deltadash/

This product mainly aimed at Subaru drivers, but it demonstrates that OBD2 isn't only used for diagnostics. Pretty much anything TechII does is covered here and more.

For VW owners :

http://www.ross-tech.com/vag-com/index.html

etc. etc. etc..

For around GBP200 owners of these cars have full access to all the data and parameters in their car's electronic systems... pretty invaluable information. Wouldn't it be nice if that were available for Saabs too?

[billj]

I've successfully used a generic OBDII interface tool to read and clear fault codes in my '96 9000 Aero, even though it is not fully OBDII compatible. The protocol is the same, it just doesn't support all the commands and fault codes required by OBDII. Earlier 9000s don't have the OBDII standard diagnostic socket.

I can even read and clear proprietary Saab fault codes but I obviously need to look them up to interpret them.

I understood Tech II used the OBD-compliant protocol, even if the car itself doesn't necessarily support all the OBDII commands and fault codes.

OBDII-compliant cars may use any one of three electrical interfaces and your OBD scan tool needs to support that. I seem to remember the 9000 ('96 on) uses the ISO interface and I imagine other Saabs are the same but don't know for sure.

[trollbooster]

[ QUOTE ]
I've successfully used a generic OBDII interface tool

[/ QUOTE ]

Thanks Bill, , any recommendations?

[billj]

I'll have to go home and check which it was. However, it's only an RS232-to-OBD converter and I had to hook it up to a laptop and manually type the commands into HyperTerminal and interpret the results.

But it wasn't very expensive. Only about £60-odd, I think.

[SJ]

I've used a scantool (ELM-scan) interface and it is the ISO protocol type for Saabs. My 9-5 is an Aero, so it is supposed to be fully OBDII anyway.

Have a look at www.scantool.net and UK distributors www.gendan.co.uk

I can't say it is very impressive in use with the basic (free) software, but I don't have any fault codes, so there's nothing much to see. I also have some more deluxe software which will do datalogging, but the antique laptop I am using makes it very slow.

If you were nearby, I'd gladly plug my OBD-wotsit into your car to try if it works?

[billj]

SJ, does that use the ELM232 device internally?
If so, that's similar to what I have (I even have a couple of the chips but never got round to building anything with them).

Where did you get the software you have (the basic stuff and the "more deluxe" stuff)?

[trollbooster]

Thanks for the offer, but for practical reasons I think I'm going to have to bite the bullet for now....

[SJ]

I bought the scantool, which I understand uses the ELM chip, from scantool.net in the USA, before I found they had UK distributors. (saved a few quid on the unit, waited weeks for the delivery).
The basic software is the free download from scantool, which lets you see fault codes. There are links to other free sources like digimoto-lite to try and tempt you into buying the full versions.
The deluxe - my other half bought me a christmas present of a genesis software disc from www.espautomotive.com . I probably wouldn't have paid that much for it, but it was a kind thought....