OBD2 Scanner on Ebay

[Howard]

Hi all ,

Just a quicky , following on from my gearbox problem and the need to get the fault codes read , i have found this on Ebay , is this the correct thing that i need to read the codes or is this for engine fault codes only ?

Sorry if it's a dumb question . :o

http://cgi.ebay.co.uk/Mercedes-Benz-C-CLK-OBDII-OBD-2-Auto-Scanner-DTC-Reset_W0QQitemZ270250840428QQcmdZViewItem?hash=ite m270250840428&_trkparms=39%3A1%7C65%3A10&_trksid=p3286.c0.m14

[Dieselman]

That's OBDII only which your car doesn't have the connector for. It may read gearbox codes but may not.
You would need a 38pin to 16pin adapter as well.

You would be better talking to talktomycar.
See:
http://www.mbclub.co.uk/forums/showthread.php?t=52998

[Howard]

I see ...

The talk to my car scanner seems to have the same connector ?

It also says that it will definately work with post 2001 cars , but only maybe with pre 2001 .... mine is a 99 ....

How about if i bought the cheap scanner in the first link and then one of these from talk to my car ?

http://cgi.ebay.co.uk/Mercedes-Benz-MB-38Pin-round-to-16Pin-Female-OBD2-DLC_W0QQitemZ290205409330QQihZ019QQcategoryZ30921Q QcmdZViewItemQQ_trksidZp1742.m153.l1262

Actually , i've just been out to the car and looked under the dash and can't even see where it would plug in ?

There is a rectangular pop out bit , but nothing behind it :crazy:

[Dieselman]

It depends on what they can read. OBDII is only designed for engine emission system malfunctions but the scanners MAY cover more codes.

Normanr's works well with the adapter cable but we don't know whether it's covering gearbox faults, or whether that's what you have.

[Howard]

So the only thing can read all the fault codes is a STAR ?

Where does it plug in ? :o

[Dieselman]

38pin connector in the fusebox in the engine bay.

We don't know whather the other scanners can read other information or not. If the car reports it ehy should be able to read it.

[stevesey]

It depends on what they can read. OBDII is only designed for engine emission system malfunctions but the scanners MAY cover more codes.

Normanr's works well with the adapter cable but we don't know whether it's covering gearbox faults, or whether that's what you have.
Would need to switch one of the pins on the 38 pin adaptor to connect to the gearbox K-Line rather than the engine management K-Line to for starters. Then if the unit is generic enough it might read the gearbox codes.

[Dieselman]

Would need to switch one of the pins on the 38 pin adaptor to connect to the gearbox K-Line rather than the engine management K-Line to for starters.

Good point, that would be Pin 10. No need for a multiplexer really as long as you have a breakout box or similar.

Pin4 outputs proper OBD ISO protocol and it appears as through Pin 15is outputting ISO L-line.
Between them, or one the K-line only, I don't know whether this would cover the whole car due to information being transferred over the CAN.

[Howard]

Well over my head guys ...... sorry .... :o

[richard]

The gearbox controller uses its own private diagnosis protocol , so a generic OBD scanner wont be able to talk to it - because it cant 'connect' to the gearbox controller let alone understand what the values it may return are



R

[stevesey]

The gearbox controller uses its own private diagnosis protocol , so a generic OBD scanner wont be able to talk to it - because it cant 'connect' to the gearbox controller let alone understand what the values it ma return are

Not that private - freediag (http://www.freediag.org/) will do the job (but yes a generic scanner wouldn't)

Must get around to knocking up an interface circuit (before something goes wrong and I need one).

[richard]

Not that private - freediag (http://www.freediag.org/) will do the job (but yes a generic scanner wouldn't)

Must get around to knocking up an interface circuit (before something goes wrong and I need one).

I wrote freediag :-)

Richard

[stevesey]

I wrote freediag :-)

Richard
Interesting - I was thinking of having a play around with the code once I get something working.

Just looking at one of these (http://www.skpang.co.uk/catalog/product_info.php?cPath=23_29&products_id=131) interfaces, which I could then wire to the back of the 38 pin connector (via a rotary switch to select different K-Lines) and route to a DB9 in the armrest.

[Dieselman]

I'd be interested in how this goes.

[richard]

Its a very long time since I looked at the code others took over (as I never had any more time, and wrote the code as a learning about diagnostics thing) (and someone said no will will write/release this code for free)

It should work with any of those max232 devices - the freediag will talk to dumb (i.e level converting interfaces such as max232) and a couple of the clever ones I came across at the time.

OBD-II protocols are quite timing sensitive, so the more clever interfaces which do the low leve comms on seperate hardware work well, but are less flexibile to some extent (such as talking to MB gearboxes !)

Richard

[stevesey]

Interface ordered.

Now I need a spare laptop with RS-232!! Although one of our spare PC's will do for starters.

[stats007]

Is there not a seperate gearbox diagnostic port you can read the codes from by the usual grounding method with an LED? I can do this on the W201 and did it on the R129s (that used the roof button to flash a number of times).

What you really want is an old HHT.