Red battery warning light R230

[Cineek]

Hello to all forum users.

I bought my dream SL500 less than a week ago. Unfortunately, due to the age, there was a problem with charging the batteries. After replacing the alternator, charging is back. The battery under the engine cover is charged 13.2V and 14.4V in the trunk. Unfortunately, there is a red battery sign on the dashboard.
After scanning the system with Delphi DS Car Max, two errors appeared:

• B1108 - Instrument cluster no longer transmits over interior CAN databus , CAN bus OFF ( Intermittent )
• B1109 - Fault in CAN communication with control unit EIS ( Intermittent )

Please help me find the problem.

Mercedes SL500 reg.FB52BXC

Thank you for any help.

 

[MikeInWimbledon]

Hi Marcin,

Welcome to the forum !

All R230's have charging issues, especially when left unused for more than a few weeks. It's the way that they were made and the way that people use them.

Which is not to say that R230's are unusable or a problem, you just need to be aware that of the potential risk if left unused, or when buying them after them sitting unused.

Who advised you to replace the alternator, and who did it? Were the batteries changed at the same time or earlier? To state the obvious, perhaps, at face value this "sounds" these OBD readings could have been triggered by the battery and alternative issue.

Electricians will be along in the minute, but the easiest path on this is to probably to talk to your local car electrician or MB Independent.

 

[NJSS]

Welcome Marcin

I have an R230, which is used occasionally in the winter and have found that keeping it connected to a decent charger, in my case a CETEK is worthwhile, if not essential.

I have CETEK connectors wired in to the battery in the boot & when not on charge plug a battery monitor to the CTEK socket so I can keep an eye on things from my 'phone.

Good luck.

NJSS

 

[oldguy57]

Hello to all forum users.

I bought my dream SL500 less than a week ago. Unfortunately, due to the age, there was a problem with charging the batteries. After replacing the alternator, charging is back. The battery under the engine cover is charged 13.2V and 14.4V in the trunk. Unfortunately, there is a red battery sign on the dashboard.
After scanning the system with Delphi DS Car Max, two errors appeared:

• B1108 - Instrument cluster no longer transmits over interior CAN databus , CAN bus OFF ( Intermittent )
• B1109 - Fault in CAN communication with control unit EIS ( Intermittent )

Please help me find the problem.

Mercedes SL500 reg.FB52BXC

Thank you for any help.

Are you sure that the alternator was replaced with the correct one? Some owners have reported problems when a "cross matched" or "equivalent" alternator has been fitted instead of a factory original. Can make a difference in some cases apparently. Could also be a problem with the battery maintenance module - not unknown in the R230, although how you test this I haven't a clue. No doubt a session on Star will reveal all.

 

[Cineek]

Are you sure that the alternator was replaced with the correct one? Some owners have reported problems when a "cross matched" or "equivalent" alternator has been fitted instead of a factory original. Can make a difference in some cases apparently. Could also be a problem with the battery maintenance module - not unknown in the R230, although how you test this I haven't a clue. No doubt a session on Star will reveal all.

It seems to be correct because the charging of the batteries has returned.
Forgive me for asking, but what is Star ?

 

[Cineek]

Hi Marcin,

Welcome to the forum !

All R230's have charging issues, especially when left unused for more than a few weeks. It's the way that they were made and the way that people use them.

Which is not to say that R230's are unusable or a problem, you just need to be aware that of the potential risk if left unused, or when buying them after them sitting unused.

Who advised you to replace the alternator, and who did it? Were the batteries changed at the same time or earlier? To state the obvious, perhaps, at face value this "sounds" these OBD readings could have been triggered by the battery and alternative issue.

Electricians will be along in the minute, but the easiest path on this is to probably to talk to your local car electrician or MB Independent.

The batteries were changed earlier than the alternator and the replacement was made by my mechanic who did my service.

 

[whitenemesis]

It seems to be correct because the charging of the batteries has returned.
Forgive me for asking, but what is Star ?

The batteries were changed earlier than the alternator and the replacement was made by my mechanic who did my service.

STAR is Mercedes diagnostic system.
The dual battery system on the R230 can be a sensitive thing and changing batteries in the wrong order can cause issues.
See attached info on the system

 

[Jobsworth]

The BNS module in the boot have given me trouble in the past, with battery warnings in the cluster that have been difficult to pin down. I keep a brand new BNS on the shelf, since trial by substitution has been the only way I have found to determine reliably if it’s faulty or not.

 

[grober]

 

[flowrider]

Since changing the battery have you reset the errors. I have recently changed my starter battery and had to reset to get rid of a load of error messages.

 

[michaelnaughton]

Since changing the battery have you reset the errors. I have recently changed my starter battery and had to reset to get rid of a load of error messages.

How do you reset these error messages?