OBDII Fault Code reader success with W202 C220 CDI

[David Pemberton]

Hello

I wanted an affordable basic diagnostics / fault code reader for my W202 C220 CDI with the 38-pin diagnostic socket, but couldn't find a definitive answer here or elsewhere. I emailed UKOBD Ltd and got a prompt helpful reply: they had a good hunch but couldn't promise. I risked a £100, and their kit works.

More below, and I'll update the thread with a second installment when I've more experience.

Best wishes

David
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Here's what UKOBD said in response to my enquiry:

"Thanks for your enquiry, as you are probably aware diesels were not required to be OBD2/EOBD compliant until 2004, however some manufacturers were compliant before this date and according to Autodata your car is, nonetheless we have no specific experience of this vehicle so I cannot give any guarantee that it will work, as such what I would suggest is that you buy the UKOBD interface ( £ 64 95 ) which comes with the Digimoto lite software and the Mercedes to OBD2 converter cable ( £ 23.99 ) and if this works then you can always update the software to the full version 5."

It was such an honest and straightforward answer that I decided to spend a £100 just to find out. (And the kit would work on my other half's Polo).

This is what I ordered:

Mercedes 38-pin to OBDII ISO converter
http://www.ukobd.co.uk/gstore/store/g_viewItem.asp?idProduct=66

UKOBDII ISO Interface with Digimoto Lite software
http://www.ukobd.co.uk/gstore/store/g_viewItem.asp?idProduct=86

USB to Serial Converter (needed for many new laptops without a serial port)
http://www.ukobd.co.uk/gstore/store/g_viewItem.asp?idProduct=10

Total cost £110.93

It arrived by next day post, took just five minutes to unpack and install, and I was up and running reading data from the car.

I'm going to upgrade to the full v5 of Digimoto and will write an update to this thread as I learn my way around the software.

 

[David Nock]

Don't really understand the above as I don't know much about modern diagnostic equipment, (old electrical engineer with a little multimeter),but I've filed it under bookmarks (favs) for future reference. Why does the 2nd link refer to petrol engines?

 

[ricko3]

all that sounds interesting,what does it do ?thanks

 

[John Kerr]

Hi David ,I would be very interested on the results you achieved with the scanner.I have a W203 220 CDI,if it works on yours should work on later models.Does it give engine fault codes?
Regards John

 

[television]

All of the readers that plug into the 38 pin socket will read engines, but for other faults and adjustments to the engine you need to be plugged into the 16 pin under the dash

 

[John Kerr]

Malcolm do you think these code readers will pick up sensor faults on diesel cars made before 2004.
Rgds John

 

[television]

Malcolm do you think these code readers will pick up sensor faults on diesel cars made before 2004.
Rgds John

I can have a look to see if that is included, but I think off hand it is not possible

 

[David Pemberton]

OK - perhaps this title should read "some success" - apologies for over enthusiasm on my part. I can read engine data per Malcolm's comments.

I'm not sure if there is a 16 pin socket on the W202 - any ideas Malcolm? Nice and obvious on my Polo, can't believe I should really have to pull the dash apart to find it (mind you same gifted design to change the pollen filter!).

 

[David Pemberton]

OK - after a day of fiddling about, comparing results from my C220 CDI and my Polo, plus a lot of searching on the Internet, here's what I've found so far:

I can read data for:

Calculated engine load value
Engine coolant temperature
Intake manifold pressure
Engine RPM
Vehicle speed
Intake air temperature
Throttle position

The on-board diagnostics on the car report that it can give MAF air flow rate, but I've not got a reading.

The on-board diagnostics also report that the car isn't meant to comply with OBD... which taken from one point of view is stating the obvious, but from another makes me wonder why it's prepared to talk to me at all.

I can get the car to report that it hasn't got any fault codes (which I expected), but this also means that I don't know what it might be able to report if it had any! If anyone can suggest any faults that are harmless and easy to induce/fix then I'll see what it has to say about them.

As well as using the Digimoto software I've also been able to communicate with the car using the standard Windows HyperTerminal software (anyone who used a Bulletin Board or a modem in the 1980s will recall this type of command line software). It makes me wonder if there is more data to be extracted from the car?

Still not found anything like the 16 pin ISO OBDII socket, too much rain today to want pull apart the under-dash trim, but suspect that car doesn't have one (all ideas to confirm/deny existence and location of said socket gratefully received)

 

[BlackC55]

Your car does not have the 16 pin socket.

Remove the air mass plug and see if you get a fault code come up.

You should get the reader to read:

Door control modules
PSE (Pneumatic System Equipment)
Engine
Gearbox
Selector module
Audio
Eis (igntion switch)
Instrument cluster
Esp


Thats what I can remember from the Star.

PLEASE Please please remember that fault codes are only a guide. Just because you may have one logged it does not mean there is a problem. Some codes always come up and the car will be operating fine.

The most important thing with diagnostics is the "Live Data". Without this fault codes do not mean much. A faulty air mass (with wires all connected to the sensor) do not often show up on petrol cars as a direct fault code. The live data will show it being ok too. Its just the way it is.

 

[television]

Just for anyone else reading the thread, the 16 pin socket came along 1998-9 onwards, at the same time as we got BAS and the OBD2 around 2000 on

 

[David Pemberton]

Hi Malcolm - the car's a was built in spring 2000 - but no sign of a 16 pin unless well hidden, BlackC55 says it doesn't have one.

BlackC55 - any idea how I get the other control units to respond, Malcolm's early post said I wouldn't get further than engine data, which indeed is all I've got so far

(There's nothing wrong with the car - I'm just experimenting for the day when it goes wrong and I can't figure it out the old fashioned way)

 

[BlackC55]

The problem is not with the control units its your software/hardware.

 

[television]

Sorry, the data link in the car was only on new models, though the 129 and others were updated the 202 was not as the 203 was imminent. it is OEBD PO compliant.

As Black55 says it needs diagnostics more than a reader

 

[Mikimogo]

Hi David,
What exactly are you using to get the 38pin Diagnosticsocket to talk to you as I have the same yr2000 C220 CDI which doesn't have the OBDII 16pin socket. I am getting nowhere at all I got an OBDII reader off ebay with a 38pin adapter cable but it just comes up as "err" I have tried a couple of pin configurations on the 38pin but to no avail and I've had no help with my postings. There must be someone out there that knows what I need to do the job but I haven't had any luck so far, I've also tried a gunson code reader that I got a few years ago, it has different leads and probes but without knowing which pins to use I am just shooting blind really. I can't take the car to a garage because its waiting to For a VIC check after an accident so it can't be taxed until after that. I just need to put out the EPC light as I think I have fixed the problem as 1 of the injector spill back pipes had split during the bump and thats what put the EPC light on and so I have replaced all 4. I would be really grateful for any advice that you may have to get me out of this fix.
Regards,
Mick

 

[David Pemberton]

Hello Michael

My "success" has been rather limited. The first item in this discussion thread gives you the list of kit I bought – all of it speculatively as no one knew what might work.

The later threads from me show you what I have been able to read (all live data). I haven’t been able to read any fault codes. My car hasn’t had a fault that would generate a code, though I did unplug the mass air sensor to try and generate a fault, but none showed up.

Getting deeper into the world of ODBII, I discovered that I could get the car to “talk” to me using a old fashioned bit of terminal software. The data that comes back makes me think that the W202 220CDI isn’t ODBII compliant in any useful way and that it will only respond to the correct proprietary software (well beyond my pocket or needs). A good independent specialist should now have the software and would be able to help you at a lower cost than the franchised network.

Best wishes

David

 

[Mark A]

I purchased one of these to work on my LR discovery V8 a year or so ago. Although it wasn't OBD compliant I contacted them and was told the same thisng as you (it will work). Set up and didn't work with my car, my wifes MGZS, and an Audi A3. After giving up I contacted the company and they said that none of them were compliant and that I couldn't get a refund. After I produced the original e-mail from the query about the discovery he put his hands in the air and gave me a partial refund (re-stocking charge). I will never be buying anything from them again.

If you do buy, ensure all communications are kept until you have confirmed that the system works.

Mark

 

[premmington]

Fault code reading can be very mis-leading. Even with the latest and most expensive kit or main dealer equipment, communication between diagnostic reader & the EEPROM chip, where the info is stored, is not always possible.**Even when possible, faultcode reading may point to sensor failure, when in fact the sensor is reading correctly, the problem is something else. Faultcode reading must only be seen as a diagnostic method "to point the finger in the right direction". To trust faultcode reading (serial data) as your only means of diagnostics, will mean allot of wasted time & money buying un-needed sensors. Sykes Pickavant equipment is as good as anything for the money, new or secondhand. Sykes ACR4 with a collection of pods & leads, is the only relevant model sold. Sykes MAP pods very good, but you will have to pay an annual subscription of about £400. The Sykes kit is available for about £1500. We use a Bosch KTS 651-750 which cost us thousands, plus you need to enter into a contract for monthly updates. But if you have a separate scope & OBD2 EOBD CAN faultcode reader & a bit of know-how, you can get round most things. Be warned! No one bit of kit however expensive it is, will do all applications. Another comprehensive bit of kit, is VIXEN as used by the AA, it's loaded onto a Panasonic Toughbook. We've used this to some success, getting hold of a copy of this may prove very difficult thou. We would not invest £7-10k+ in the Bosch KTS system again, as most applications can be covered by separate handheld kit purchased over the net. Now coming available, at very low cost on the internet is PC based EOB2 faultcode reading kit for 2001+ petrol cars & 2004+ diesel cars for connection via USB. Elm from the USA, has a good name in the trade, its very tricky to use thou. Elm now sell vehicle manufacturer specific kits for about £100. VAG-COM is excellent at £200, serial & USB leads are available from eBay for less than &10. GM's Tech2 dealer spec kit, is now available from eBay ex Australia, badged up as Opeltech. Renault Clip is good value for money now. *Forget Snap-on scanners & Crypton code readers. Software & updates just not up to the expensive price tag. Launch systems are good but expensive, daily updates over the internet seems a bit excessive. We have used most systems, none are as good as the marketing literature & salesman say they are! Basically if you have a laptop, go on eBay & you are very handy with a PC, all serial data extraction software is available, at very low cost. Autologic BMW, Mercedes, Land Rover and Volvo is sold for £7999.00 for each manufacturer, including a rubber covered laptop, the software is available online marketed under the name Carsoft for £60.00 each. We have Merc Star diagnostic kit, we paid a fortune for it. Yes it works well, but it has its limitations & we will never earn enough form it to cover the purchase price. Now coming on the market are very well made small two line LCD orange coloured faultcode readers, made in Spain. Which read most protocols, EOBD is the one you will need most, they cost £70 ish. A blue one is available for VW-VAG group cars which does ABS as well, cost £40ish. Also available from China, is a multi OBD 2 II Can Code Reader OBD-A422 which*costs about £47 (22-05-06) its the cheapest nastiest looking test instrument I've ever touched, but works very-very well on petrol cars from 2001 and diesel cars from 2004. If you buy any faultcode reading kit, it must be Can compliant and be able to read the new type 29 bit identifiers (Can 2.0B) as well as the old 11 bit identifiers (Can 2.0A). Even if you don't understand this, it is a question you need to ask when buying diagnostic equipment.
Don't dabble with programming, we caught a cold with Siemens software for BMW. It kept crashing, simple additions (nodes) to can-bus systems for PDC enacted by BMW main dealers, ended up with cars being driven into the workshop for the job and then subsequently being towed away. The simple reason being the software did not work. You have been warned... Any re-programming is best undertaken by the main dealer. Simple reason is, if it goes wrong its down to them! Paying a main dealer for one or two hour's labour, is nothing compared to the risks involved. Any "run of the mill" programming to position of diesel injectors and the like. Can be overcome by searching the internet and buying pre-programmed parts from pattern part manufacturers. Key programming & auto locksmithing is a discipline on its own. If you have the Sykes Map kit, for £375 they do an additional pod that covers most common applications. Any job that this kit does not cover, we call in a mobile auto locksmith. Even in our busy workshop, we do not get enough key programming work to justify £5-7k on more comprehensive kit. Some well priced flash coding kit for fitting second-hand ECUs is now coming on to the internet for sale, from the USA. The whole unit hardware/software costs less than one monthly software update with the big named manufacturers. Serial data output (sensor graphing) via the old style K+L-line, or the newer superior Can hi-low terminals of any diagnostic socket, K-line outputs have a data rate of 10400bps where Can2.0A is 500.000bps and Can2.0B is 1.000.000bps. Output that is supplied by the ECU & displayed by Tech2, Bosch KTS , later Snap-on & main dealer spec diagnostic equipment including Merc Star. It's all unreliable & misleading. Apart from adding cabling and test equipment to the circuit in question thus increasing the margin of error. It does not exclude the host vehicle cabling, where over 50% of the faults are situated. Any volt drop or resistance in the host cabling will alter the results, giving the impression a perfectly functioning sensor is at fault. Plus with Can-Lin networks, any data transfer glitch will show as complete network failure. When in fact the definitive but time consuming method is to backprobe both ends of all of the network links between the multiplexers (nodes) with a dual channel oscilloscope, comparing the stored waveforms, subsequently they need to be identical for the system to work. As a matter of info, most people fear Can-Lin bus systems, but in fact they are very simple & reliable. All network inputs/outputs are testable & most faults are caused by glitches which can be traced back to electrical interference (noise) from high output coils, ignition, central locking solenoids etc. etc. Some early systems lacked shielding and had little or no thought put into where the can-bus cables were routed. Higher or lower frequency interference (noise) will be very evident when comparing waveforms recorded on to an oscilloscope. Mildly damp connections cause problems, they don't need to be wet or corroded, just damp! Forget WD40 or duck oil, use compressed air from an airline fitted with water trap to dry connectors.

text from http://www.remmington.plus.com