mercedes handheld diagnostics

[John Peerce]

Hi All. I would like to know if anyone here can advise on getting a handheld OBD-II diagnostic codes reader for mercedes cars (post 1996).

I noticed that the plug for the OBD computer inside the engine bay of my car (W202 1999 C43) is circular shaped (with 30 or so pins in it) and, having done done some search on the internet the OBD-II readers that i saw have a rectangular shaped connector...

Also apparently with some OBD readers you can hook them up to the car's computer from inside the cabin - so you can monitor the car and at what points error codes arise while driving .. has anyone got experience of this ? where is the plug for the OBD reader located exactly inside the cabin ?

 

[fuzzer]

On my car (w203) its located under a flap in the drivers side footwell.

Those machines cost a fortune. I don't think its worth your while getting one. TBH

 

[Glideman]

Try http://www.snapon.com/uk/ they have stuff like that.

 

[scotth_uk]

Mercedes enthusiast magazine's advertising section lists a company that specialises in this stuff. About 300-400 quid for a Windows 98 box I seem to remember.

 

[John Peerce]

Thanks for all the replies so far.

I will follow up the suggestions noted above on getting these readers.

My reasons for asking about getting one of those OBD readers is that recently my car started cutting out while driving. Took it to the Mercedes specialist, who hooked it up to an OBD reader, and discovered that the mass air sensor has been sending error codes to the fault memory for a while, plus error codes came out showing many cylinders have been misfiring (which if not corrected early on can kill a cat converter over time costing £££) etc.

Note that Mercedes cars made for the American market have a "check engine" light on the dashboard, which normally lights up when error codes are sent, thereby providing an early warning to owners to take it to a tech to have it checked. European cars don’t come with that.

For European owners of Mercedes cars, unless one does a regular diagnostic test, you will not know that there is a problem (eg O2 sensor, MAS, cylinders misfiring) until perhaps more serious issues develop with the car (such as in my case), with the added cost of repair and inconvenience.

I probably wouldn’t want to pay more than £200 for the whole reader and connector kit. Having said that, i think this will pay for easily pay for itself over time through the savings made by diagnosing problems early on.

Do you guys agree with this ?

P.S. my car cutting out problem is still not resolved. MAS sensor changed (which improved the response of the car, but hasent solved the actual problem), Fuel Pump relay changed, L5 crank sensor next to be changed this coming Saturday.

 

[Will]

Hi mate,
Welcome to the forum.
Sorry to be the bearer of bad news but you will not be able to buy one of those for anything near £200.
Try multiplying by 10 then adding a bit!
As far as I know, on some more basic cars, the fault code readers are quite cheap. To read the Mercedes system, the diagnostic equipment "Interrogates" the car and retrieves the fault information.
Hope this may help your decision?
Cheers,
Will

 

[John Peerce]

Thanks for the replies all,

Ok my intial research on these "handheld OBD" devices does indeed show them to be expensive.

I am now moving in another interesting direction: instead of getting an actual handheld device, some companies provide software that is installed on a windows laoptop, which does much more detailed and informative analysis of diagnostics than simply reading codes. The cost of the software is reasonable (about £140 ($225)).

Here is the link to one such company, there maybe others (cheaper ?) :

http://www.autoenginuity.com/products.html

I myself have a windows laptop gathering dust, so maybe I can put this into some good use. Note that a connector is needed from the laptop to OBD socket in the car, and i haven’t looked into the type of connector and cost of it (maybe an adapter is needed too etc .. )

Any opinions on this, will it work on a Mercedes car ? it seems very promising to me..

BTW, does anyone know where the OBD socket is INSIDE the car cabin ? I know there is socket inside the engine bay, but as i understand it there is one inside the cabin too for monitroing the car while driving (note my car is a 1999 W202 c-class C43 , but i expect that the location of this socket will be the same in other mercedes cars).

 

[jimmy]

I am friends with a good local garage, they have the Bosch equipment to diagnose most cars excpet MB's. They have to take MB's to the local dealer for fault codes or resetting problems.

It's something to do with the connector, I think MB dont allow people to copy their unique plug. I am pretty sure there is only one diagnostics socket and that is under the bonnet with the ECU.

I have seen and done this with other cars and a laptop sat on the passenger seat with a cable out of the window and under the bonnet to the diagnostic port. You can see things such as RPM, Voltage, fuel mixture, temperatures etc. Obviously doesnt mean much unless you know what you are looking for. The laptop was a pretty basic one, I expect the software and connectors cost lots though.

 

[Maff]

Maybe of use to you for starters...

http://freediag.sourceforge.net/

Writen by a fellow board member

 

[Alps]

Jimmy,

this is to change from the end of this year tho! my mate (who works for MB) say the equipment will be availible at a cost of £15K, inlcludes computer, docking station, and all the leads.

 

[John Peerce]

£15K !!! for a test kit !

I am still thinking along the line of buying software from a company such as the one i mentioned earlier for say £140 (or any other similar company).. but the tricky bit is to find a connector cable that will go from the USB port/or serial port of the laptop from one end, and at the other end fit in the OBD socket in the car's engine bay. Problem is that the cable that comes with this software has standard OBD connector that fits American Mercedes cars, but not the round 38pin socket that is found in European Mercedes cars. As Jimmy mentions above, the 38 pin plug seems to be unique to mercedes...

I also wonder if the connector from the laptop to the OBD socket in the negine is enough, maybe an adapter or some other "module" is also needed...

Any ideas ?

 

[scotth_uk]

Try Maverick Technologies

 

[Alps]

John,

hehe

i was talking about the full diagnostics computer as in their workshop...slightly off on a tangent there!

 

[crawfy58]

Interesting topic this.
I have an A Class which has a 16 pin OBD socket under the dash next to the bonnet release lever.
Does this mean that it I could connect up to my laptop with a product like the one at www.autoenginuity.com.
I am a little confused because you are saying you have 30 pin connectors and MB use special connectors but mine looks like a standard OBD type.
Please enlighten me.
Thanks,
Crawfy

EDIT:
Just looked at the Carsoft stuff on the Maverick Technology site and they cover all the different types of connector ,

Included in the kit is:
All required Diagnostic Cables
Original 3 - Pin connector ( W201 - W124 - W126 - W129 )
Original 38 - PIN connector ( for 1991 - 2000 vehicles )
Original OBD 2 connector ( for 2000 - and up vehicles )
The Complete Software for all MB vehicle types from 1988 until April 2003

Hope that clears things up a bit.
Crawfy

 

[John Peerce]

crawfy58, thanks for claryfying this.

I only got as far as checking the user manual of the AutoEngenuity product (pdf file on the website) and in it on page 8 there is a picture of a their cable being hooked up to a 16 pin OBD socket under the dashboard.. here is the link (scroll the pdf file down to page 8):

http://www.autoenginuity.com/dloads/scantool_user_guide.pdf

the impression i am beginning to get is that newer Mercedes cars sold in Europe may well have OBD-II socket inside the car. The reason i say this is that in addition to your comment, in an earlier message the owner also says that the OBD socket in his car is in the footwell area, covered by a flap. My car is from 1999, but being a C-Class W202, the design is older than 1999, so it may well be that it doesn’t have an OBD socket inside the car.( I have looked already couldn't see it , will look again tonight)

 

[crawfy58]

Thanks. I've looked at the picture and yes mine is a standard type connector.
At least we know a bit more now anyway.
Thanks,
Crawfy

 

[Msmax]

There are 2 types of interfaces: ODB and ODBII also called EOBD.

Benzine cars produced after 2000 for the european markets must have the standard OBDII 16 pin interface installed near the driver within a range of 1 meter. For diesel cars from 2003.

For the US market this started already in 1996.

The old ODB interface had a 38pin socket installed in the boot near the fuses. As is with my E-290TD from 1996.

The units advertized are mainly for ODBII systems.
I'm not sure yet if the software and interface also will work with ODB systems.

THe Maverick one seems to interface with both.
Any idea about the price?
Here is some info about the old connector:

ODBI connector

 

[Mark300SL]

I spoke to Maverick ages ago about buying a system

Here is their reply - received in Feb this year

Dear Mark,

Thank you for your enquiry . Please find MB Diagnosis and MB Information system details atached.

Apart from pricing information which is contained or attached to this email reply, our website contains ALL THE TECHNICAL INFORMATION ON OUR PRODUCT.

Prices for the Professional Carsoft Diagnostic systems are:

MB V7.0 @ £1479.00 (Euro 2400)
MB CISMB1 @ £ 449.00 (Euro 780)
Free UPS delivery & Discounts apply for multiple systems purchase. To see the prices in your local currency at todays rates, please got to www.oanda.com/convert/classic

Each Carsoft system is complete with software and cables (system does not include Laptop/PC) to cover all vehicles listed in the appropriate application lists (See www.mavericktechnology.co.uk/?carsoft.htm )

Updates are released each year and average around £300 p/a per system. The exact price depends on what new models, systems or features have been added. Updates are optional. All clients are made aware of the new updates by mail or email.

The Carsoft Information System for Mercedes-Benz (CIS) is the first Totally Integrated workshop information system for MB. Available to supplement the Carsoft MB diagnostic system, the 'CIS' program "automatically" selects all the technical information of the fault in question and will then offer: Component Location, Technical Explanation with pictures, a complete Wiring Diagram of the system in question, and " Step by Step" repair assistance.(www.mavericktechnology.co.uk/?cis.htm )

Min. Spec. for PC/ Laptop for Carsoft or DEC:
P1 150 MHZ, 32 MB RAM, CDROM & floppy drive, 600 X 800 screen resolution, 9 pin Serial Port on Com1, Win 95.98.ME. (Carsoft BMW V6.1 now also supports XP/2000. D.E.C. fully supports XP/2000)

All products carry a 12 month warranty and worldwide telephone support.

All prices quoted are excluding shipping & taxes (where applicable) respectively.

We deliver worldwide by UPS, from stock.

Payment can be made by Cheque, Credit Card or Bank Transfer in Pounds Sterling only.

Please contact us for an on-site demonstration (UK only) or an Order Form.

Thank you,
Regards

Andrew Steer
Maverick Technology
T: 00 44 (0)1280 816333 F: 00 44 (0)1280 816111

 

[Msmax]

As I understood the data available on the ODBI connector is the same which can be shown on cars with Climate control units installed.

Means if "REST" is pressed while engine is running (or switch in I position) then the display will show in the left the item and in the right the data.

I don't know all the meanings of the different items yet, but it is a start. Is still not the same as with a laptop with a lot of extra information like schematics etc, but is for free.

Maybe it is a good idea to go after the meaning of all these codes.

The ones I know (english ones also found here at MBClub):
01 = Innerraumtemperatursensor in C° (KA)
02 = Außentemperatursensor (S)
03 = Wärmetauscher links in C° (KA)
04 = Wärmetauscher rechts in C° (KA)
05 = Verdampfer in bar (KA)
06 = Motor Kühlwasser in in C° (Z)
07 = Kühlsystem in bar (KA)
08 = Kühlsystem in C° (Z)
09 = ?
10 = Kühler, bzw. Lüfter/Stromaufnahme in Volt (KA)
11 = Emissionssensor/Stromaufnahme in Volt (KA)
12 = Sonnensensor/Stromaufnahme in Volt (KA)
20 = Kühler, bzw. Lüfter/Stromaufnahme in ma (KA)
21 = U/min - Anzeige * 1000 (Z)
22 = Geschwindigkeit ohne Tachoabweichung (!) (Z)
23 = Stromaufnahme Batterie in % (KA)
24 = Batteriespannung in Volt (KA)

01: Interior temp sensor
02: Ambient temp sensor
05: Evaporator temp. sensor
06: Engine coolant temp.
07: refrigerant pressure
08: refrigerant temp.
16: carbon monoxide value
17: nitrogen oxide value
18: dewpoint temp.
21: engine RPM
22: vehicle speed
24: battery voltage

 

[John Peerce]

Msmax, thanks, that is very interesting info.

any document on the internet anywhere which has full instructions on this and complete list of what can be displayed ?

i wonder if error codes from the fault memory can be shown (for example P0300 cylinders misfiring etc).. .. that would be so useful !

What would also be useful is a list of what the normal range of these values should be. For example, i know that battery volatage is around 11-14 volts, so below or above would indicate problem etc.

I note that some numbers are missing from the list between 00-24, why is that ?

I can't wait to go home to try this !!