Autoelectrics problem MB C320

Gotta love all these clever computers in cars.

$4000 to fix the problem sounds like a lot of money, but compared to the price of the car, it seems normal to me, for a prestige car. What did that one cost new? $100k? It's also an economies of scale thing, IMHO.

Keep that in mind when comparing it to the WRX.

There are devices available now that keep enough power in the car to stop the radio, etc. from losing their settings. If the person replacing the battery uses one of these, you won't need to worry about PIN codes, etc..

Also, the first place to look when a late model vehicle is having sensor problems is the earth wires between the negative post of the battery, the body and engine. It is common to find that the original wires are too small and cause sensor malfunctions. A new battery may well mask a minor wiring inadequacy.

Family bought a new V6 VW Passat in January 1999, with a 3yr/100,000km warranty. Transmission completely let go in 2004 with 130,000 km on it. Because it had always been serviced on time and at the same VW service, we ended up paying for half the labour of fitting the NEW transmission that was supplied FOC by VW Australia (about $600). It took a fair bit of haggling to get there but we felt we got quite a good result.

Those are very bizarre symptoms indeed. At least your car kept on going, whereas mine would going to a limp home mode locking into one gear, which is very annoying if you only have one car in the family. I wonder how a manual version would be affected (Does Mercedes Benz have manual cars???) in my case.

Cheers.

I learnt a lesson that day disconnecting the battery. However the comment about disconnecting the Mercedes-Benz's battery more or less followed Daryl's suggestion to disconnect the battery to see if that can reset the computers (or at least that's what I thought he was meaning). The Mercedes-Benz does have well marked points where I can connect a set of jumper leads to another car battery whilst I change the faulty one, which should eliminate the risk of having no electricity running through the computers/stereos.

As an update, I followed through with charging the battery this morning by starting the car and letting it run. The fault appeared immediately. I left the engine running whilst having breakfast. Stopping the car and then restarting when we were ready to leave saw the errors disappear, and never came back for the day, which does support the theory of a weakened battery. I am still puzzled why the car would start fairly easily, and yet threw the error codes, as I would imagine the voltage and current from the alternator would kick in fairly early. The funny thing is that if Mercedes-Benz and other car manufacturers can make all these sensors for errors, why can't they incorporate a sensor for a dying battery, to indicate when it is time to change the battery prior to other computers throwing all these error codes.

I had a look at the size of the battery, and it is quite a large and unusual one labelled N88 (stopping me from running into Kmart or Supercheap to get one). The service station near where I worked had to order one in, which means that I won't be able to get a new battery until tomorrow.

Still, I am very disappointed with Mercedes-Benz for not diagnosing the battery as a possible fault. Playing the sceptical consumer, I wonder if the car was in warranty, would I be told differently as to where the fault lies.

If the battery replacement solve the problem, I will be the first to ring the Mercedes-Benz service managers, to let them know of my feelings on the matter.

For those who may consider buying a Mercedes-Benz, I hope you take all this into consideration.

Cheers

The C320 was $100k new. However, Mercedes-Benz do have lower spec models starting from high $50ks. I have checked the Mercedes-Benz website, and these models also have ABS, ESP, BAS, which means that they also share the same part has gone faulty (or maybe not given that I will be checking out the battery theory) in my car. I can't imagine how an owner of a $50+ car would feel with a $4000 repair bill.

$100k sounds a lot for a car, but all the luxury features do cost money to put together, though for this particular model, the premium charged seemed to be more in the spirit of the engine size/engineering. "Wheels" mag certainly questions the value of this particular model (compared to lower spec models) and frankly, I personally agree.

In any case, although I realise that the cost of R&D into these technologies need to be recuperated, the cost of manufacturing a PCB with a few chips on it can't be that high.

Cheers.

That's not bad haggling at all there, considering that it was out of warranty and reasonably high mileage.

I have yet to hear from Mercedes-Benz Australia. The service manager stated that he has e-mailed Mercedes-Benz Australia to request a special price. That was two or three days ago. I wonder how long it would take unless I do some pushing. However, I don't think they would give me a part which they would normally charge $4000.

Now that puts the costs for me into perspective, i.e. $4000 for a computer part against $600 for whole new transmission!!!

Cheers.

I think it has something to do with one cell of the battery (6) that is weakened or dying... So I am not surprised...

Discussing this thread with my step-dad last night - apparently from

30,000 he'd mentioned to the service advisor that the transmission didn't feel right and asked the advisor to check it out. He did this at each subsequent service and they kept coming back saying there was nothing wrong. Luckily though, they'd kept records of his concerns (which, BTW, were completely un-related to what caused it to eventually fail) and these records were used by the dealer to show VW Aus. that a problem existed from well within the warranty period. Either way, it was the dealer that did all the haggling on our behalf. I'm sure a suggested offer of a bottle of Wild Turkey or similar to the advisor might have an influence! ; )

A voltmeter across the battery terminals whilst starting may revel whats happening. I suspect because of a weak battery there is a significant voltage drop whilst cranking, the sensors will be operating outside their parameters because of the low voltage and will throw up a fault code. The fault codes would have already been detected before the alternator is charging so a weak battery as the cause makes sense. Maybe the MB computer system should have someway of disregarding fault codes whilst the engine is cranking?

Daryl

Have you had any aftermarket electronics installed on the car?

My '99 E430 (which I *love*) had seme aftermarket connections to a cell phone booster from the previous owner that was draining the battery. I have similar but not as severe electronic gremlins as the battery discharged over time (the reason he sold it to me cheap). Fixing that electrical "leak" has cleared up all of the problems and I have been running trouble free for 3 years now.

Hi everyone,

The car does not have any aftermarket electronics installed. Everything was installed by MB including the cradle for the mobile phone.

As an update, I had a new battery put in today. $140 later and I thought everything was cured. Picked the car up from the local service station and it ran smoothly. Then on the way home this evening, the codes appeared again! ARGGGGGGG!!!!

However, it took 10 mins into the journey before it appeared, and stopping and restarting the car again took the gremlins away all the way home. Surely it can't be a fault in a new battery as it would have appeared soon after starting.

I hope the fault does not lie in the ESP control module, but this does not look good.

Thoughts anyone? The only other thing I could do would be following Daryl's suggestion of cleaning all the contacts to the ESP module. However, I will consider getting the original owner to bring it into another MB service centre to get a second opinion.

However I will see what it does tomorrow morning as for the last few days, the faults appear almost straight away on starting, but does not appear at all on the journey to work.

Still yet to hear from MB Australia however on what discount offer I will receive.

Looking more like a Lexus IS is coming into my garage soon (though personally an MX 5 hardtop would be much nicer :-))).

Cheers.

I didn't know MB makes cell phones

and who made the all the other things that escaped you ? I wonder..

>

??? The owner said "everything was installed by MB", I at least read it that the car has a genuine MB cell phone kit, the cell phone may be after market but one intended for the genuine car kit should not drain the battery dead.

Since this was a C-model car, it cannot be the second battery that has caused problems in some E-class cars. I cannot help but sure hope you get good advice and get the car running well and enjoy it.

The cradle was installed by MB. It was an option when the car was designed back in 2001 and accepts Nokia models. Of course, nowadays, they don't need these cradles (which would become obsolete quickly anyway as phone models change so quickly) as I would imagine the newer models would have Bluetooth options.

Cheers.

I put the phone in a 'lations Kompressor at a fraction of the cost of MB charges ( phone was 400$ cheaper) , it's never missed a beat so it cant be hard to get the install right , now is yours working everything 100% ?

A friend bought a 2005 C200 Kompressor recently. He did not order a phone system for his car. Instead, he got a Blueant bluetooth unit which he leaves permanently on his visor. Cost - $180 ish.

I guess he doesn't mind recharging it (or put fresh batteries in everyso often) and does not mind not having the feature of dialing via the steering wheel buttons.

Anyway, the battery was not the solution. This morning, the fault codes appeared again on starting. The only thing that I have learnt to do is warm up the engine and then the fault would go away.

I wonder if the heat from the engine bay improves a connection somewhere (hoping that it has nothing to do with the ESP control module), but how would I go about finding where it is missing. If I drive the car into MB for a diagnostic, the heat would keep the fault away so they can't diagnose it. I can imagine the only way is leave the car with MB overnight so that they can test it in the morning cold. ?Thoughts

Cheers.