Can one undo the EPS controller connector and its earth or do you need STAR to reconfigure it ?

Submariner1

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I saw one poster with similar issues, he cured it by undoing the connector in the back of the N47-5 ESP Controller and cleaned the corroded terminals and all was good thereafter.

Q. Can I just switch off, key out and undo the ESP Controller connector, and the ESP-ABS Ground connection (there seems a little corrosion under the clear plastic sleeving)
6C3760E0-5751-4D36-9DC5-1882C8873F9D.jpeg
Or will I have to have STAR to “Commission” control unit N47-5?

Note WIS says if you “remove / install” the N47-5 you need STAR. But are they assuming a new replacement unit? I.e. do you if you just remove the connector?
Hopefully not, as surely thats not disimilar to disconnecting the battery .. is it?

The only other thing I can do is clean up the terminals in the prefuse box. Its pretty open to the elements at the side.
FE97DAA5-A067-4382-8346-3D83EB8D370A.jpeg
Thats if I can get the lid off its not budging a mm! :(

The negative - ground terminal has a O.00 Ohms resistance to the body earth so that seems fine.

Now waiting for the battery to die, and by replaced by Mobilo

Then as soon as thats done, if that doesnt resolve it perfectly then its going off to my Indy.

 

John Laidlaw

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I’d get it to Colin already Peter, it’s looking like a ‘mare!
Honestly yup are having the worst ever luck with that car. I admire your fortitude I gave up on the SL long before your would have I think!
 
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Submariner1

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This crazy battery was at 12.2V with the door just shut.
Recovered to 12.5V when shutdown with a 50mA drain.
Left it 30 mins and it climbed back to 12.8V!
And she started beautifully with no messages

It must be an undervoltage thing.
Or I think some intermittant short inside the battery ( like the first one).
 

LostKiwi

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If you disconnect the battery you can undo any connection without any problems.
 
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Submariner1

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If you disconnect the battery you can undo any connection without any problems.
Thanks Allistair
I might try it as it worked for one chap.
As I have time before the battery dies.
 
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Submariner1

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Wishful thinking ....
Its 3 days since she was CTEK charged.
As expected.
Just after opening the doors she was at 12.1V and recovered to 12.3V in a few minutes.
Climbed in, assuming opening the door woud drop her to 12.1V

Fully expected as a minimum
A guaranteed “Abs and esp unavailable” orange msg.
And in light of the low voltage
An “Eps inoperative” and probably as she was so low the “Parking Brake” red msg.

And hey presto .... NO MESSAGES!

Tried the start again .
No Messages :-/
Kinda destroys my low voltage theory??

Only Caveat I used the Key not the KLG button ... but that should not change things??
(Note I have never had a fault code on the KLG module even when she was acting up)

One should be delighted, but in light of the fact 2x I have got heavy steering with these faults.
I know the issue is not resolved, and dread paying for hours of fruitless diagnostics if they cant find the issue.

Pretty difficult to diagnose a fault that is not currently acting up!

:(:(:(
 

Botus

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you know its std for the ABS units to play up on most cars?
DTF rubbish, looking here they guys that fixed my bike one, list this one as a common one to play up.
I find it intriguing few on this forum ever complain about this ABS fault, maybe merc take the b grade ones and not c grade like the rest of UK vehicles?

http://www.ecutesting.com/catalogue/mercedes_eculist.html?category=4047&model=722

here's how to fix the BM one yourself

 

Botus

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Wishful thinking ....
Its 3 days since she was CTEK charged.

I don't think a CTEC charger can put out enough grunt to charge this battery.

I was away for 18 days, the Merc was at 11.6v and the focus was unable to crank. Unfortunately my bigger charger was at a different location, so I put a small modern bike one on the Merc, it can only output 1.1 amps, after 2 hours the car was at 12.1v so I was going to leave it.

Stupidly, I'd parked the Merc 18 inches too far up the drive to get the motorbike out. So 30 mins later, I unlocked it again and had to turn the ****** key on to get out of P.... whilst still leaving on charge! hand brake off, out of park, roll 18" back into Park and hand brake on and key out, must have been less than 40 seconds but rechecking battery it was now at 11.8v and I'd had the ignition on, so no doubt full of low volt error messages and stupidly in the computers !!!

Later that day, having used a gadget to start the Focus I drove it 4 miles and plugged in to my more powerful charger. After 2 hours it went to 14v and 2.8 amps before it had fully charged the battery in 3 hours and switched to maintenance mode.

Plugged same charger on the Merc when I got back and it started pushing 12.6v 3.64 amps and 4 days later still plugged in. usually this 3 amps phase is a 24 hour time wasting session and lucky if it shows 13.1V at the end
 
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Submariner1

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I don't think a CTEC charger can put out enough grunt to charge this battery.

I was away for 18 days, the Merc was at 11.6v and the focus was unable to crank. Unfortunately my bigger charger was at a different location, so I put a small modern bike one on the Merc, it can only output 1.1 amps, after 2 hours the car was at 12.1v so I was going to leave it.

Stupidly, I'd parked the Merc 18 inches too far up the drive to get the motorbike out. So 30 mins later, I unlocked it again and had to turn the ****** key on to get out of P.... whilst still leaving on charge! hand brake off, out of park, roll 18" back into Park and hand brake on and key out, must have been less than 40 seconds but rechecking battery it was now at 11.8v and I'd had the ignition on, so no doubt full of low volt error messages and stupidly in the computers !!!

Later that day, having used a gadget to start the Focus I drove it 4 miles and plugged in to my more powerful charger. After 2 hours it went to 14v and 2.8 amps before it had fully charged the battery in 3 hours and switched to maintenance mode.

Plugged same charger on the Merc when I got back and it started pushing 12.6v 3.64 amps and 4 days later still plugged in. usually this 3 amps phase is a 24 hour time wasting session and lucky if it shows 13.1V at the end

I assumed when it went into “Care Mode” it was fully charged?
Its a 3.56A max charger. They say good for 120AH battery but no mention of CC ?
From flat ... It starts at 3.5A and says 12.4V across the battery terminals, the voltage gradually rises to 14.8V and the amps correspondingly lower. Normally after 10 to 14 hours its at 180mA, then it flicks into care mode, and the voltage drops to 13.8V. With circa 160mA.
I thought that meant it had gone through the whole cycle and was charged?
[Note one of my points of interest, is sometimes it can get to Care Mode in 4 hours! ... makes me suspect the battery is iffy and tricking the CTEK ]

Once in care mode, if read quickly the battery shows 13.1V and after 3 hours it drops to 12.8V
But then it starts to degrade by the hour.
Clamp meter on (min max mode) shows 30mA min to 60mA max drain.

What throws me is how this battery can increase its voltage post the stabilisation residual charge stage. Without driving or charging ( shutdown ) can miraculously increase from 12.5V to 12.7V! ( with no change in drain value.

Sure many are bored shitless with this, but I need to wait till it drops out and reproduces messages and get a new battery from Mobilo. And then get it on STAR.

IMO no point in paying for STAR until the battery is a know good quantity.

For example today started at 12.1V 3 short shopping trips under 6 miles each way.
And no fault messages!
And I played the stereo full on.
 
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Submariner1

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I’d get it to Colin already Peter, it’s looking like a ‘mare!
Honestly yup are having the worst ever luck with that car. I admire your fortitude I gave up on the SL long before your would have I think!

Hi John,
Getting there very fast ... we buy any car :)
I had hoped today to get Mobilo out, change the battery and if that didnt cure it ALL like it did last time.
Its off to Colin.

And guess what ... she is running perfectly ... no fault codes no dash messages!

Call me stupid but as all the symptoms are identical to the problems with the defective battery, I want them to replace the battery before spending money on diagnosis.
Yep I hear those who say you cant get 2 duff batteries, but they were made in the same month! Batch problem I am sure.

And I am not stupidly stuborn regarding getting a proper battery check .... just dont fancy paying for it / them, when the last defective one PASSED the full xentry and star battery test 3 times in a row!
I was lucky that time as Mobilo is free, and when he finally said well sorry but its fine. I had the dogged approach of asking him to start the car .... and thank god it couldnt even engage the starter cogs. So a fourth battery test then showed 54A CC not 850A and 9.2V.

I wasted a lot of time, because I didnt beleive I could have a second battery problem. And then as I needed to use the car, I couldnt let her run down the voltage till she failed and call out mobilo.

Hence seeing wheel sensor fault codes I assumed It was sensible to clean them and the reluctor rings .. thanks to LK I now know the difference between the msg. And code types i.e those suggesting visual inspection and take some user action and those saying visit workshop!
Mine dont say visit workshop ... so fundamentally the item isnt broken, ... all the more it points to undervoltage ... battery issues.

Well I am not charging her again till she breaks! :)
 

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I think if it starts with 12.3v showing, the computers play ball, if its lower they have a moment.

If its 12.6v (which it mostly is even after a charge) when I put the key in you can't do a full diagnostic check (25 to 40 mins, start to finish) without it complaining by module 16 (out of 50) and flashing errors for low voltage messages in all subsequent modules.... even if it was fully charged for 24 hrs beforehand.

I have to remember to flick the charger back off maint mode to full power (the car eats 3.47 amps with the key on and not started) - even then I see voltage depleting during diagnostics (and that's with diagnostics loaded off my faster memory card that runs quicker)
 

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I think if it starts with 12.3v showing, the computers play ball, if its lower they have a moment.

If its 12.6v (which it mostly is even after a charge) when I put the key in you can't do a full diagnostic check (25 to 40 mins, start to finish) without it complaining by module 16 (out of 50) and flashing errors for low voltage messages in all subsequent modules.... even if it was fully charged for 24 hrs beforehand.

I have to remember to flick the charger back off maint mode to full power (the car eats 3.47 amps with the key on and not started) - even then I see voltage depleting during diagnostics (and that's with diagnostics loaded off my faster memory card that runs quicker)

W221 has a 35 amp load on the electrical system with key on engine off. Xentry moans that you must connect a large power supply to the car when doing diagnosis. I use a 13.5v 66amp supply.
 
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Submariner1

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W221 has a 35 amp load on the electrical system with key on engine off. Xentry moans that you must connect a large power supply to the car when doing diagnosis. I use a 13.5v 66amp supply.
Do you mean in key Pos1 or key Pos2 (but the latter with the engine off ).
Reason I ask is, I was told by MB that I could use my 3.6A CTEK to power the car during a Comand update in Position 1. Best With everything else off.

I noticed WIS says to power my CL during Diagnostics (assume in key Pos 2.) you need a minimum power supply of 30As

Just checking he was right about key Position 1. Being oK with only 3.6A and Comand on
 

alexanderfoti

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Do you mean in key Pos1 or key Pos2 (but the latter with the engine off ).
Reason I ask is, I was told by MB that I could use my 3.6A CTEK to power the car during a Comand update in Position 1. Best With everything else off.

I noticed WIS says to power my CL during Diagnostics (assume in key Pos 2.) you need a minimum power supply of 30As

Just checking he was right about key Position 1. Being oK with only 3.6A and Comand on

I don't need the key on pos one to be turn on comand but yes I mean pos 2.
 

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W221 has a 35 amp load on the electrical system with key on engine off. Xentry moans that you must connect a large power supply to the car when doing diagnosis. I use a 13.5v 66amp supply.

An approx. 0.5kW load or put another way 0.67 bhp :confused:

Pure madness, no wonder the battery cannot charge adequately during short runs.
 

alexanderfoti

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An approx. 0.5kW load or put another way 0.67 bhp :confused:

Pure madness, no wonder the battery cannot charge adequately during short runs.

Most of them have a 220 amp alternator, but you can't dump a huge amount of current into a lead acid that easily. Even at 30 amps charging current, a half flat 100ah battery will take over an hour to fully recharge.
 

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I read these posts not understanding most of it and can see how helpful this forum is, I am glad that these things are beyond my comprehension.

I get stressed taking the plastic cover off my battery just to give it a light cleaning.

:)

Robin
 

LostKiwi

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Charging rate is determined by voltage difference between the battery and alternator and the internal resistance of the battery. As the battery starts to charge to voltage difference reduces so the charge rate reduces. Its very difficult to charge a lead acid or AGM battery very quickly and from flat can take in excess of 4 hours no matter how big the alternator.
 


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