Scanners vs. Grey Matter and the Search 2002 ML320 - PeachParts Mercedes-Benz Forum

Martin Wolf · #1 07-16-2012, 01:12 PM

Just purchased a 2002 ML320 and here we go. I have to admit, probably have spent way too much time on this forum already, but what a resource. It has been invaluable in getting my 300e to 230k.

For the ml 320-Key locking problems-must be a bad actuator, funky blower function-most likely a control motor. Bad hatch struts-replaced easy. Some paint chips and light corrosion - a bit of body work no big deal.

What is curious to me is the following: The access to a MB competent scanner sounds like either a ton of money or trips back and forth to a shop. Is it true that even if a failed component is replaced, function may not be restored due to stored codes, or will these be over ridden by new component? Does this depend on the component? Sounds like transmission codes need to be erased.

The whole problem solving paradigm using the forum, suggests that experience from the group may be more powerful or even replace need for scanner to diagnose, ie. common failures, symptoms, part examination, can usually lead to isolation and identification of the failed component.

Replacement of the failed component is usually straight forward following MB protocols from All Data, or even better prior experience on the forum. But alas, if this is not sufficient due to need for code erasing, than a scanner is truly needed for the DYIer.

What has been most peoples solution to this dilemma? How many have gotten by without a scanner entirely, and what are the cost effective solutions for obtaining a suitable scanner. I know that DAS is outside of our control, but what about everything else? Can all systems be accessed by the OBD port, or do you have to actually connect to each computer subsystem?

Does anyone know of a good resource that discusses in depth the scanning and diagnostic systems of MB on a technical level that would be useful in further understanding the details of the system?

Thanks,

Marty

mbdoc · #2 07-17-2012, 09:48 AM

Owning a scanner that can get into ALL of those systems is most likely too $$$
ON ebay you can find Chinese SDS clones that would do that if you are willing to drop at least $1-1.5K.

All of the diagnosis is done thru the ODB2 port.

Getting a W163 DVD or going to startekinfo for a day or 2 reading about technical functions of each of the systems.

Martin Wolf · #3 07-17-2012, 11:54 AM

Mbdoc,

Thanks for the reply. At what point, should the DYI be able to separate from the dealership? Will our vehicles eventually become old enough that the dealer will no longer want them in the shop? It sounds crazy, but will classic parts eventually sell a scanner to us? I think the W163 already is starting to look vintage in that classic way.

The diagnostic and functional power of ECU readout is truly astonishing when compared to the old days, yet your experience and insight in many ways more than makes up for the lack of a scanner to diagnose. Unfortunately, being able to reset systems means there is still a dependence on a capable scanner. Is there a short list of items that need factory scanner reset after fault resolution? A list of common failures that do not?

Thanks

Marty

mbdoc · #4 07-17-2012, 01:29 PM

Almost every function on a ML requires computer diagnosis...
even interior lighting.

Dealers usually wean cars after 15 years.

MANY indies have the same quality scanner that the dealers use..

Whiskeydan · #5 08-16-2012, 06:59 PM

So, there are fault codes that can only be reset by the dealer?

I suspect a bad coil pack on #7 on the ML55. Intermittent miss and check eng light. I caught it in the act by unplugging #7 and noting no change in idle whereas others had a major effect.
I hate to be dependent on the dealer to 'reset' for a simple fix.

mbdoc · #6 08-17-2012, 09:23 AM

Engine faults can be reset by MOST ODB2 sacnners.