SL/R230: Electrical problem? Ugggggh!
Thread Starter
Junior Member
Joined: Aug 2022
Posts: 22
Likes: 1
2004 SL500
Electrical problem? Ugggggh!
So after replacing my gas tank. Works like a charm! Putting gas like a champ. I decided to change both batteries. Used to get a message in the morning that the electric was offline. Was told to do both. After that, was driving her about 25 miles to the GWB in NY. Stopped the car for about 5 minutes. When I tried to restart, it just kept on trying but couldn't turn over. Called AAA and was told that it would be 45 minutes. After 20 minutes it started, but got my first check engine light. It was the crankshaft position sensor. Changed it. Yesterday I was driving on the highway. After about an hour the display keeps on lighting up as if it is shutting down but I was still driving. I was getting all kinds of warnings to visit the workshop or a picture of the battery or even that the retractable roof was bad. It would do it for about a minute or two and then calm down for about 20 minutes or so and start it again. Last time it happened, my hazards went on and would not shut off for the next 30 minutes. Saw something about an 80 amp fuse? A problem with the EIS? Any ideas? Batteries are both less than 2 weeks old.
Super Member
Joined: Sep 2018
Posts: 746
Likes: 184
From: Melbourne, Australia
2005 SL 500 R230
Firstly I wouldn't connect the issues at this stage. Failing rear batteries are a semi-regular cost of ownership. Your front battery was probably OK unless you had slow cranking issues.
It's good to have a fresh rear battery.
CPS issues can come at any time; it's a good one to change as a preventative item.
Check your windscreen drains for signs of blockages. There were posts recently about blocked drains causing water ingress into the connections to the SAM / fuse boxe modules. This sounds like it might be your issue. If doing a scan you've probably got a list of codes which you can clear, then see what comes back.
It's good to have a fresh rear battery.
CPS issues can come at any time; it's a good one to change as a preventative item.
Check your windscreen drains for signs of blockages. There were posts recently about blocked drains causing water ingress into the connections to the SAM / fuse boxe modules. This sounds like it might be your issue. If doing a scan you've probably got a list of codes which you can clear, then see what comes back.
Thread Starter
Junior Member
Joined: Aug 2022
Posts: 22
Likes: 1
2004 SL500
Firstly I wouldn't connect the issues at this stage. Failing rear batteries are a semi-regular cost of ownership. Your front battery was probably OK unless you had slow cranking issues.
It's good to have a fresh rear battery.
CPS issues can come at any time; it's a good one to change as a preventative item.
Check your windscreen drains for signs of blockages. There were posts recently about blocked drains causing water ingress into the connections to the SAM / fuse boxe modules. This sounds like it might be your issue. If doing a scan you've probably got a list of codes which you can clear, then see what comes back.
It's good to have a fresh rear battery.
CPS issues can come at any time; it's a good one to change as a preventative item.
Check your windscreen drains for signs of blockages. There were posts recently about blocked drains causing water ingress into the connections to the SAM / fuse boxe modules. This sounds like it might be your issue. If doing a scan you've probably got a list of codes which you can clear, then see what comes back.
Super Member
Joined: Sep 2018
Posts: 746
Likes: 184
From: Melbourne, Australia
2005 SL 500 R230
The engine will run without the belt, therefore without the alternator, so it sounds unlikely that that would be your issue. The alternator / regulator is a pretty simple thing.
Have you checked the charging voltage on both batteries?
Have you checked the charging voltage on both batteries?
Thread Starter
Junior Member
Joined: Aug 2022
Posts: 22
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2004 SL500
Yes, was ok. But I got the battery lights on the dash while driving. Could be the brushes inside rubbing and it creates a short.
Super Member
Joined: Sep 2018
Posts: 746
Likes: 184
From: Melbourne, Australia
2005 SL 500 R230
A dead short there would have blown F52/2 - the 200A fuse. Might have been a momentary internal short which could have triggered the red code.
Post back with your progress. Interesting one. (But not for you - just a headache...)
Post back with your progress. Interesting one. (But not for you - just a headache...)
Thread Starter
Junior Member
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2004 SL500
I’ll post again after it’s changed. I’m going to chalk it up as another $1000 towards preventive care on an old beautiful car. If it works, great! If not, not sure what else it could be. From just first glance the vents look clean.
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Thread Starter
Junior Member
Joined: Aug 2022
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2004 SL500
Alternator was changed. Car, drive wise, is riding smoothly. Paid less than one thousand for the alternator into the car, so i'm happy. Have 2 new Mercedes batteries in the car and a new Crankshaft Position Sensor. Hopefully I can go at least 2 years with only regular maintenance, and I would be thrilled! I know I need 4 tires soon, mine are at 5-6mm's, but hopefully besides that, only oil changes. Thanks for your help.
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Super Member
Joined: Sep 2018
Posts: 746
Likes: 184
From: Melbourne, Australia
2005 SL 500 R230
Good job! Looking at the circuit, I have no idea why that would have caused those errors; a spurious fault in the regulator board maybe. I hope the fault doesn't come back.
Thread Starter
Junior Member
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2004 SL500
Well, actually just took the car out now, and it just lit up on and off like a Christmas tree once again. Different this time was the roof lever on the center console was blinking on and off red. Fuel level was stuck at empty even though the tank was full. The one fault I got was Fuel Reserve almost gone. Range was 83 miles. 20 minutes later, car was driving the whole time, it was back to normal running smoothly. Not sure what all this means or what to do. Not sure whether to take it to a local mechanic or the dealer.
Super Member
Joined: Sep 2018
Posts: 746
Likes: 184
From: Melbourne, Australia
2005 SL 500 R230
It was unlikely to be the alternator, as mentioned.
Forget the dealer if you don't want to be reamed.
As mentioned, I'd be pulling the SAMs and inspecting the connections. If you don't want to do it yourself, you need a good independent specialist.
Forget the dealer if you don't want to be reamed.
As mentioned, I'd be pulling the SAMs and inspecting the connections. If you don't want to do it yourself, you need a good independent specialist.
MBWorld Fanatic!
Joined: Mar 2018
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From: Netherlands
2005 R 230 SL350 (M112 3.7). Sold the 1966 W113 230SL recently
Deng, this incident is getting a real pain. My experience with a faulty EIS was that seemingly unrelated gremlins started to play up: wipers, Comand, seat belt tensioner and more (I happily don't remember) were playing up intermittently. Replacing the EIS was the 100% cure. In a forum I read that someone with a similar nightmare could momentarily fix it by tapping his ignition key. You might want to do that, as a possible clue.
Thread Starter
Junior Member
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2004 SL500
Deng, this incident is getting a real pain. My experience with a faulty EIS was that seemingly unrelated gremlins started to play up: wipers, Comand, seat belt tensioner and more (I happily don't remember) were playing up intermittently. Replacing the EIS was the 100% cure. In a forum I read that someone with a similar nightmare could momentarily fix it by tapping his ignition key. You might want to do that, as a possible clue.
MBWorld Fanatic!
Joined: Mar 2018
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From: Netherlands
2005 R 230 SL350 (M112 3.7). Sold the 1966 W113 230SL recently
I honestly don't know what an EIS can and cannot mess up but it's a lot. It's good to know that your three SAM's and the EIS communicate continuously about every action and routine check that run through the system. In many cases it is EIS that authorizes action requests. Diagnosis systems can be frustrated by a faulty EIS as it is the main port of entry for their quest.
EXPERTS - do shoot me down if the above is inaccurate. Wanting to learn every day..
EXPERTS - do shoot me down if the above is inaccurate. Wanting to learn every day..
Super Member
Joined: Sep 2018
Posts: 746
Likes: 184
From: Melbourne, Australia
2005 SL 500 R230
EIS faults usually manifest as intermittent or no-start issues. Strange how Fred's caused those errors.
The CEL when taking off the petrol cap was probably caused by a blockage or failure in the evaporative purge system. (You can have more than one fault going on at once...)
The CEL when taking off the petrol cap was probably caused by a blockage or failure in the evaporative purge system. (You can have more than one fault going on at once...)
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Joined: Mar 2018
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From: Netherlands
2005 R 230 SL350 (M112 3.7). Sold the 1966 W113 230SL recently
I insisted on having the EIS replaced and MB made me sign a document voiding their risk because diag didn't point at it. Tada all problems gone for ever and the car has behaved flawlessly ever since (4 yrs).
Thread Starter
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2004 SL500
Well you just never can be certain but EIS is pivotal in canbus. My first encounter was when switching on the wipers nothing happened on the windscreen but the seat belt tensioner would jump into action and the nav went dead. Gradually gremlins would show up anywhere (roll bar clicking being one of them) when I wanted wiping. A German MB dealer replaced wiper motor and mechanism, rear battery and a SAM. Not one bit of improvement. (The guy I bought the car from covered cost).
I insisted on having the EIS replaced and MB made me sign a document voiding their risk because diag didn't point at it. Tada all problems gone for ever and the car has behaved flawlessly ever since (4 yrs).
I insisted on having the EIS replaced and MB made me sign a document voiding their risk because diag didn't point at it. Tada all problems gone for ever and the car has behaved flawlessly ever since (4 yrs).
MBWorld Fanatic!
Joined: Mar 2018
Posts: 1,442
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From: Netherlands
2005 R 230 SL350 (M112 3.7). Sold the 1966 W113 230SL recently
A new EIS can only be installed by an MB dealer because it has to be 'married' to the car and it 'freezes' to the codes of your car after a certain number of starts. By design, it can not be used in any other car after that.
In Europe dealers need online coding from Stuttgart which they say takes like an hour or so.
There are shops that say they can repair and perhaps hack an EIS, no coding needed when you get your own piece back from them. I didn't go that route and paid something like € 1.200 for a new one. (At least they still have them, as opposed to new BCM's).
All this doesn't say that your EIS is faulty but I do have a hunch.
In Europe dealers need online coding from Stuttgart which they say takes like an hour or so.
There are shops that say they can repair and perhaps hack an EIS, no coding needed when you get your own piece back from them. I didn't go that route and paid something like € 1.200 for a new one. (At least they still have them, as opposed to new BCM's).
All this doesn't say that your EIS is faulty but I do have a hunch.
Thread Starter
Junior Member
Joined: Aug 2022
Posts: 22
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2004 SL500
Seems to be acting a lot better for the past few days. A mechanic neighbor of mine suggested changing the batteries in the key fob. He seemed to think that all basic systems running in the car on start-up get their instructions from the fob. Makes sense? One of them actually is still not blinking red and he suggests doing both just because its close by. At this point any fix that only costs $6.59, i'll try without question!
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From: Gretna, NE
'03 SL55 Black, '03 SL500's Aegean, Mars Red, Tazanite, Alabaster, '11 S550 Flint Gray
Makes no sense, at least for an R230. Car should function fine with totally dead batteries in the fob. Power for the immobilizer function is provided inductively by the EIS so that low fob batteries will not leave you stranded. Keyless go and remote functions won't work, but you can unlock the door with the mechanical key and start by inserting the fob.
Thread Starter
Junior Member
Joined: Aug 2022
Posts: 22
Likes: 1
2004 SL500
Well you just never can be certain but EIS is pivotal in canbus. My first encounter was when switching on the wipers nothing happened on the windscreen but the seat belt tensioner would jump into action and the nav went dead. Gradually gremlins would show up anywhere (roll bar clicking being one of them) when I wanted wiping. A German MB dealer replaced wiper motor and mechanism, rear battery and a SAM. Not one bit of improvement. (The guy I bought the car from covered cost).
I insisted on having the EIS replaced and MB made me sign a document voiding their risk because diag didn't point at it. Tada all problems gone for ever and the car has behaved flawlessly ever since (4 yrs).
I insisted on having the EIS replaced and MB made me sign a document voiding their risk because diag didn't point at it. Tada all problems gone for ever and the car has behaved flawlessly ever since (4 yrs).
Firstly I wouldn't connect the issues at this stage. Failing rear batteries are a semi-regular cost of ownership. Your front battery was probably OK unless you had slow cranking issues.
It's good to have a fresh rear battery.
CPS issues can come at any time; it's a good one to change as a preventative item.
Check your windscreen drains for signs of blockages. There were posts recently about blocked drains causing water ingress into the connections to the SAM / fuse boxe modules. This sounds like it might be your issue. If doing a scan you've probably got a list of codes which you can clear, then see what comes back.
It's good to have a fresh rear battery.
CPS issues can come at any time; it's a good one to change as a preventative item.
Check your windscreen drains for signs of blockages. There were posts recently about blocked drains causing water ingress into the connections to the SAM / fuse boxe modules. This sounds like it might be your issue. If doing a scan you've probably got a list of codes which you can clear, then see what comes back.
Thread Starter
Junior Member
Joined: Aug 2022
Posts: 22
Likes: 1
2004 SL500
I wish you can see the condition of this car. I wish you can sit and drive this beast. It is a smooth beautiful ride and hugs the curves at 80mph like as if it was brand new. Besides for this problem, which by the way doesn't effect the running of the car, she is a fabulous car. What should I do with it? Throw it into a junk yard? There has to be a way to diagnose what the issue is and fix it.
MBWorld Fanatic!
Joined: Mar 2018
Posts: 1,442
Likes: 260
From: Netherlands
2005 R 230 SL350 (M112 3.7). Sold the 1966 W113 230SL recently
IF, yes if, the EIS is your culprit it will likely frustrate a proper diagnosis because the EIS is part of the route diagnosis runs through. This is way in my case the (German..) dealer threw parts at the car three times without any improvement. Saying; IF diagnosis fails to shed a proper light then I'd say go for it and get your EIS fixed because you like/love the beast. Probably cheaper than selling a cripled car and getting another one.
Thread Starter
Junior Member
Joined: Aug 2022
Posts: 22
Likes: 1
2004 SL500
IF, yes if, the EIS is your culprit it will likely frustrate a proper diagnosis because the EIS is part of the route diagnosis runs through. This is way in my case the (German..) dealer threw parts at the car three times without any improvement. Saying; IF diagnosis fails to shed a proper light then I'd say go for it and get your EIS fixed because you like/love the beast. Probably cheaper than selling a cripled car and getting another one.
