Outside temp
Is the probe still in the grill by fog lamp?

Rest, first instinct would be battery with so many issues.
We know from others that a poor battery causes a host of electrical issues.

Scan shows nothing?
Did either garage use SDS scan?

And our expert on this sort of thing
@Dave2302

 

Battery for sure.....all those electronic gremlins!!! how old is your battery? don't know? get a new one asap

 

Got to be worth putting a meter on the car to see what voltage is there, a cheap and easy test to start with!

 

Outside temp is weird - 0,0 deg C is the freezing point and it's +8 deg C here now.

Battery is 2 years old and doing fine. Just went out and measured 12,5 V.

The Indy is a MB-indy and he has the all correct tools. The scan took 10 minutes, but I didn't get the codes.

 

Is the alternator charging ok?

 

Yes, the charging is OK (close to 14 V when starting, then dropping slowly to some 13+ V

 

I'd need to see the SDS Print Out before I comment

 

I didn't want to ask him for that, he was a bit busy. Just happy he could scan the car. ESP control module - msot likely. And all the issues in point 1 to 9 are refering to speed readings, as far as I understand.

 

There's a lot of other much less expensive stuff it could be, that's why I won't comment without SDS Fault Codes Print Out

 

We don't want you playing parts darts if there is no need.
Having the codes helps to avoid that cost.

Just in case.
Parts darts, randomly throwing new parts at car only to find it was a part costing next to nothing.

 

Anyway, I did change the battery, just in case......... and the faults stayed away during a 10 km trip. I am totally amazed, can a battery die in a running car? And then show full voltage afterwards? When the faults first appeared I had driven the car for 20 km from start.

I am not convinced that it was the battery, but hopfylly or hopfylly not, it will show in time. But can I trust the car now?

Many thanks for your inputs before!

 

a dead or dying cell, even one out of 6, can fool one into believing the battery is still good. time will tell
when you say change the battery, you put in a new one or just swapped one battery for another, in unknown condition?

 

THIS^

 

also remember to synch your windows and change the time on your clock

 

When I have my little indicator plugged into the ciggy lighter (I don't know if it's "loaded"), it always shows a minimum of 14.3V when driving. Never as low as 13.

Maybe your alt is starting to fail? If that has any effect? Just a "what if".

 

The "old" battery was bought and installed just a year ago. It's marked April 2019. The battery that was before that lasted - guess what - just a year. And, yes, I have them on a CTEK during winter.

This battery in the car now is bought today.

The Voltage in the dash shows a stable 14 V (13,9 to 14,1) along time after start. After 45 minutes drive it slowly drops to 13,3 or 13,5.

 

Maybe the ctek cooks your battery.

 

My battery when driving starts at about 14.3 as it is charging the battery and then drops to 13.3 etc after a while as the battery charges to 12.6/7

are the batteries u r buying MB batteries? they are warrantied for only 2 years

 

No MB batteries. Varta and Tudor.

I have heard of battries going dead while driving - in rally cars. Not on a SLK on a Motorway.... and then recover so I could easliy start the car at least 10 times (while trying to clear codes).

 

not the expert but as mentioned, a battery with a dead or dying cell, still has 5 cells working as they should, but that one cell can get the electronic gremlins to hold a meeting and next thing you know....what happens happens
my ctek 3.4 has a step that sees if the battery is able to even be charged

 

I had a 2005 SLK55 AMG with only a second battery through 120,000 miles of use and two owners, me being owner #2. I had a similar issue like the OP with error codes but mine was diagnosed as a fuel line electrical that fried. Was repaired at an MB dealership (~$1200). They told me I was lucky that it was just the electrical line to the fuel pump.

I never use CTEK or battery tender... and my battery lasts forever. My current 350 is 6x,xxx miles, 8 years since delivered to the MB dealer (June 2012), and still on same battery. Knock on wood.

Curious as to why or how the SLK seem to "eat" or wear down its battery so quickly...

 

I had a 2005 SLK55 AMG with only a second battery through 120,000 miles of use and two owners, me being owner #2. I had a similar issue like the OP with error codes but mine was diagnosed as a fuel line electrical that fried. Was repaired at an MB dealership (~$1200). They told me I was lucky that it was just the electrical line to the fuel pump.

I never use CTEK or battery tender... and my battery lasts forever. My current 350 is 6x,xxx miles, 8 years since delivered to the MB dealer (June 2012), and still on same battery. Knock on wood.

Curious as to why or how the SLK seem to "eat" or wear down its battery so quickly...

some have a Smarttop (early versions used more juice) or any 3rd part power stuff like cameras or radar detectors, etc

 

@Swedish Steven,

Here's how it works in simpler terms, A Starter Motor will crank an Engine even at 10.5 Volts.

ALL post circa 1997 Mercedes monitor Voltages. A volt meter in Cig Lighter, Dash Display etc is not a good indication of Battery condition, I'm not sayin' it's a bad thing, but the only sure fire way to check a Battery is with a Heavy Discharge "DROP" Tester, basically a Voltmeter with a scale and a big Heating Element built in ............. NOT WITH ENGINE RUNNING, OR KEY IN IGN !!

Certain ECU's, like f.e. Traction Ctrl, Transmission, PSE, EIS, etc etc will shut down and pop a "Voltage" Code at way more, like some will pop it at just under 12 Volts.

So from this we can see that it is quite feasible for a weak Battery to start the Car, but it may be dropping to say 10.5 Volts whilst Cranking, so then when you are started and drive off you can get issues because another Module like Traction, Trans etc has seen LOW Voltage and in laymans terms, thrown a fit, thrown a wobbler, chucked teddy outta the crib etc etc

This is exactly why I wanted to see the print out, because potentially you could have spent $2000 getting a Module replaced when there was nothing wrong wi' it

It might still need replaced, but signs are good so far. Modules don't fix themselves.

It might also have been a bad connection, bad relay, bad fuse etc etc etc, all of which cost way less that $1000 +++++++++++++++

NB Voltage Figures quoted may vary they are merely just quotes for sake of example to illustrate my point

HTH,

 

I am with you all the way now. Didn't know about this:

"So from this we can see that it is quite feasible for a weak Battery to start the Car, but it may be dropping to say 10.5 Volts whilst Cranking, so then when you are started and drive off you can get issues because another Module like Traction, Trans etc has seen LOW Voltage and in laymans terms, thrown a fit, thrown a wobbler, chucked teddy outta the crib etc etc "

 

Couple of years ago I had driven about 1/2 mile when I realised none of the dash was working. Turned out that the + ancillary battery connection was not tight.

Maya~Taptalk

 

It wasen't the battery, after all. Drove to the office today (with the brand new battery in the car) and the same faults as in #1 appeared. Looks like the ESP box after all

 

Looks like the ESP box after all

Once again, what are the Codes .........................

How's about thinking of the cheaper options, like Relays, Connections, Fuses loose or bad, Speed Sensor intermittent, and a whole host of others ...................

Give me the Codes etc and I'll be able to tell you whether you are just about to waste £1000 +++++++++++++++++ ..........................

Or not

 

Maybe is time to invest in das setup. Pm me for more details.

 

Thank you, i860. I really appreciate your help. But I am a bit concerned about the learning curve here..... I am thinking in the line of a much simpler system, i.e. iCarsoft MBII...

 

Thing is no matter what you read iCS does not even do 1/3rd of what an SDS Machine will do.

OK so it's a learning curve, that is what the forum is here for, it's not that difficult, especially if you imagine that it is translated from German, so for example when you want Live Data, look in "Actual Values", a Full All Modules Code Read ? ............. "Quick Test" etc etc etc

 

Tomrrow I will go back to the Indy to get all codes. But something is for shure wrong with the car. Since I parked it exactly two days ago and until I took it to work this morning, I lost 20% of the Ah in the battery. After a 40 minutes drive to the office I was still at 80% and during the day I lost another 20%. See incl pic. The alternator is doing its job with 14 V.

Can a faulty module drain the battery when the car is off and locked? Now I put it on a charger and I also measured the drain with a clamp ampmeter. The positive going to the engine block was 0, but the other postive showed 0,5 A drain.