Electronics in MB - better these days?

[Kingpin!]

I've heard that MB used to have more fault-prone electronics in their cars prior to 2007, is this true?

If this is in fact true, is the year 2007 correct or how is it possible to know how to check it when buying a used car?

Is it the same for all models?

Also, what kind of problems could (possibly) be expected if buying an older car (for example a 2006)?

TIA!

 

[grober]

Quite often improvements occur with existing model facelifts. This perhaps allows manufacturers to make radical changes to systems rather than mere modifications. They might for example change wiring loom suppliers/design and or component suppliers. Wholesale changes would simply not be practical or economic on an ad hoc basis during production except in the extreme situation which puts an unacceptable number of cars off the road- even then the supply of alternative replacement parts can be problematic. As a general rule the longer a model is produced the more reliable it becomes as all potential faults emerge and are addressed. Then the inevitable happens a new model comes out and the whole cycle starts again. Some models do acquire a reputation for greater reliability which is probably related to the degree of testing prior to release and decisions on the quality of components used but these are a guide only and ultimately any individual car is as good as how well its been looked after. The W204 is reckoned to be better built than the W203 that preceded it but dropped the ball for a while with the piezo-electric diesel injectors. The later post facelift W211 is reckoned to be much more reliable than the pre-facelift model- they dropped the problematic Sensotronic brakes for example. Paintwork marked improved around 2003-2004 but some would say is still not up to VAG standards. All I can say is do your homework on the model you are interested in = [ This forum /other MB forums and the Honest John website are good places to start] then assess the actual car you are interested in carefully. No matter how well they made it at the factory- a few uncaring owners can wreck any car.

 

[Kingpin!]

Quite often improvements occur with existing model facelifts. This perhaps allows manufacturers to make radical changes to systems rather than mere modifications. They might for example change wiring loom suppliers/design and or component suppliers. Wholesale changes would simply not be practical or economic on an ad hoc basis during production except in the extreme situation which puts an unacceptable number of cars off the road- even then the supply of alternative replacement parts can be problematic. As a general rule the longer a model is produced the more reliable it becomes as all potential faults emerge and are addressed. Then the inevitable happens a new model comes out and the whole cycle starts again. Some models do acquire a reputation for greater reliability which is probably related to the degree of testing prior to release and decisions on the quality of components used but these are a guide only and ultimately any individual car is as good as how well its been looked after. The W204 is reckoned to be better built than the W203 that preceded it but dropped the ball for a while with the piezo-electric diesel injectors. The later post facelift W211 is reckoned to be much more reliable than the pre-facelift model- they dropped the problematic Sensotronic brakes for example. Paintwork marked improved around 2003-2004 but some would say is still not up to VAG standards. All I can say is do your homework on the model you are interested in = [ This forum /other MB forums and the Honest John website are good places to start] then assess the actual car you are interested in carefully. No matter how well they made it at the factory- a few uncaring owners can wreck any car.

Thanks for the answer!

The thing I heard has been from 2 different salesmen (not the same dealer) that MB have had a "general" (model-independent) improvements regarding the electronics in their cars and that has also affected how they offer warranties on used cars (e.g "Junge Sterne" etc.). Quite simply the basic message was that a new "era" began a few years ago.

For example, I know that MB had problems with rust around 2000 (more on some specific models I understand) and that they improved that some years later to more normal levels.

 

[grober]

Mercedes certainly made a big play of how they had uncreased model reliability dating from the introduction of the W204 C class and subsequent models dating from 2007 onwards. Perhaps its when the various CanBus Systems reached maturity- bit more circuit redundancy- better programming-better plating on the connectors etc etc . That said the temptation is always to stretch existing technology to its limits. Since 2007 when the W204 C Class was introduced with what were well proven powertrains at the time = M271 petrols OM646 diesels 5 speed automatic transmissions etc --- they have " evolved" = new diesel engines with twin turbos with piezo injectors- new turbocharged direct injection versions of the petrols and the 7 speed gearbox [ 2 generations thereof] and perhaps the biggest potential problem the stop start system- they now have 3 batteries to go wrong. Its therefore impossible to say the post 2007 W204 is a very reliable model without saying which version ? That said it does appear to be a well screwed together car so maybe that initial now much modified design is holding up well. It remains to be seen how much of that improvement is carried over into the forthcoming W205. The best tip I can offer for the prospective owner of a modern Mercedes is invest in a good quality intelligent battery charger and hook it up to the car frequently. Keeping the battery and electrics in good shape will help stave off many problems in the future.

 

[Tinkerer]

Forget the electronics, when the chassis rots away and the wheels fall off the car you might as well look for something else. No-one can weld good metal to rust! Also remember that a salesman is what it says and he/she will tell you anything to get a sale. As has been said do you own homework even if it means getting the car on a lift and insisting on getting the underside covers off ........... Oh no sir you are not allowed in the workshop! you might get hurt ....... me bitter?

 

[dnoyce]

For what it's worth, I have owned a W204 for the past 4 and a half years
and the only replacements have been tyres. Otherwise faultless.

David

 

[Geoff A]

Had mine 10 weeks (a 12-plate C350 Sport Estate) and it has been brilliant up until last night, when it threw an electronic wobbly good and proper.
Car was parked for two days at Gatwick long stay and when the engine was started, all steering wheel controls and stalk functions failed totally, and I was staring at two large orange warning lights on the dash all the way home plus messages for no tyre pressure monitoring, no ESP and no T/C I think: so no different to drive than my TVR.
Couldn't access any of the data in the middle of the speedo. Luckily I had brake lights and I made it home ok. Oddly, the rain sensing wipers worked when it rained - maybe a safety default - even though they were all switched to off.
I stopped the car on two occasions (wondering if it would ever restart) and hoped that a power off/lock/unlock would reset things. No such luck.
Comand, phone, media, leccy windows, power tailgate, auto lights, engine and trans all perfect.
Apologies to all who I offended by not indicating from Gatwick to Oxford - all I needed was a set of BMW badges.....
Needless to say, it all works perfectly this morning. I expect the faults will be logged and I will be on to MB today.
Anyone else had similar?

 

[E270 Owner]

Had mine 10 weeks (a 12-plate C350 Sport Estate) and it has been brilliant up until last night, when it threw an electronic wobbly good and proper.
Car was parked for two days at Gatwick long stay and when the engine was started, all steering wheel controls and stalk functions failed totally, and I was staring at two large orange warning lights on the dash all the way home plus messages for no tyre pressure monitoring, no ESP and no T/C I think: so no different to drive than my TVR.
Couldn't access any of the data in the middle of the speedo. Luckily I had brake lights and I made it home ok. Oddly, the rain sensing wipers worked when it rained - maybe a safety default - even though they were all switched to off.
I stopped the car on two occasions (wondering if it would ever restart) and hoped that a power off/lock/unlock would reset things. No such luck.
Comand, phone, media, leccy windows, power tailgate, auto lights, engine and trans all perfect.
Apologies to all who I offended by not indicating from Gatwick to Oxford - all I needed was a set of BMW badges.....
Needless to say, it all works perfectly this morning. I expect the faults will be logged and I will be on to MB today.
Anyone else had similar?

It was probably sulking you left it for 2 days.......

 

[Marku]

The Viano told me the other day that the parking sensors and air bags were not working and I should visit an MB workshop. Did that all day and then the next they worked. A few weeks ago it decided not to read the Sat Nav dvd. That went on for some time and then it was OK and worked fine. I am convinced that it has a mind of its own or that it is a cunning plan to get more work for MB dealers.

Apart from that there were significant quality problems at MB between 99 and 06 when they went for world domination with big increases in production. Line problems were left to the dealers to sort out under warranty and electronics testing was reduced. Warranty work was accounting for about 2/3 of workshop time.

 

[peter49]

For what it's worth, I have owned a W204 for the past 4 and a half years
and the only replacements have been tyres. Otherwise faultless.

David

Mine, a V6 diesel, is coming up for 6 years and same as yours. Terrific.