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Hello, i have problem solving this faut code: 9cc5-LM: No message, LIN (RLS).
I think that faut is coming after engine start, if i delete fault on engine running it will never come back while driving, after i leave car for a maybe 1hour , after engine start fault will come back and its always intermittent. ISTA measuring plan checks voltage from LM with ignition on and its 11.8v and its shuold be between 12-14v acoording to ISTA, after voltage check ISTA says that LM should be changed, if i do this on engine running, it says that voltage is ok and fault can be deleted.
Changed:
1. New RLSS from BMW,
2. New LIN bus chip's in LM,
3.New Battery,
4.New OEM voltage regulator on alternator,.
I Add screenshot from newtis, can someone can help explane what aditional arrows means on 12v wire and ground wire? My guessing that they connected with other wire. From fuse 1 wire and then its like Y connection made to share 12v with other components.
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Last edited by Bmwpower530; 10-14-2022 at 11:09 PM.
It means the line also supplies power to the device listed.
11.8v is low for a 12v battery. I don't understand you changing everything but what ISTA pointed you to change. If your alternator is supplying 12-14v at all times but your LM has 11.8v then the module needs to be replaced. With ignition on your battery supplies the necessary 12v. With the car running your alternator supplies the 12-14v. If your battery and alternator was doing that then it's the module. When you started the car it gets the correct voltage meaning alternator is good. You should of only tested the battery to make sure it's good. Now that you replaced the battery you only have one thing left the LM.
I dont understand you "seanjordan20" why i should change LM module that all car have 11.8v with ignition on. Not just LM module.
That would be a question for BMW. You used ISTA to find the issue. It told you the issue but you did everything but what ISTA told you was the problem just to continue to have the problem? I'm not troubleshooting the car so don't know what you've done or see other than what you have in your initial post. Again, I'm not understanding why you did everything but what ISTA told you was the issue. Maybe shed light on what made you get a battery, change LIN chips, swap out regulator, etc.
Battery was 5 years old, i was hoping that new will hold more than 11.8v with ignition on and it was for two days 12.1-12.2v . After new battery installed and registered, strange charging voltage started. After car start 14.1-14.3v, drive for a 200 metres reading drops to 12,4v like its not charging at all , driving ~15km more readings drops 12.4-12v, then rise to 12.9v and holds for 50km of my trip, trip ends i parked car to my friends house and leave it running because my boy was sleeping in a car, readings on idle rised to 14.1-14.3v.
Driving back to hove it was already dark, so lights on, same voltage readings, just after rain started and wipers swiched on voltage rised from 12.9v to 14.1-14.3v while driving and stays to end of trip (~30km) was left to home.
Couple month ago brushes on alternator was gone, i changed just brushes, so after these voltage readings i changed coplete regulator.
LIN bus chips, i had them at home, it was a cheep try to solve fault, 20€+1,5h labor.
RLSS i think have 6 lighs sense diodes on it , 2 of them was always at higher parameter. So changing RLSS was not just a try to solve fault code, and i think now FLA works correct
Today i dont feel that i was doing everything wrong trying to solve this fault code. Go and order new LM for 486€ for a try , because Ista says that, not smart. I work on cars repair for 14 years and i know that repair eletronics its not just change modules. Not always ISTA or other diagnostics tools are redirecting us to real issue.
BTW, "seanjordan20" thanks for wiring diagram explanation.
Last edited by Bmwpower530; 10-16-2022 at 01:48 AM.
Update: i measured voltage at RLSS connector 7.3v ignition on, 8.3v engine running, on fuse 56 both sides 12.3v just unlocked car, no ignition.
Now i dont understand wirings diagram again. I have to measure circuits. If supply voltage goes to RLSS direct from fuse 56, i dont know why it should drop so much on RLSS connector.
Last edited by Bmwpower530; 10-16-2022 at 03:22 AM.
IBS will be juggling around the charge current of the alternator, and so you can't expect it to stay constant like other cars. That's why it's all over the place as you are experiencing.
11.8 VDC is clearly too low for ignition ON, you have something pulling things down, aka parasitic draw. It might be the LM or something else. You'll need to isolate by pulling fuses or disconnecting modules.
Whoa whoa pump your brakes now. No one said to go buy a new LM. That would be crazy. I've had 4 modules go bad in my car and not once have I bought new. When a module is in question I go right down to the local junk yard and grab another (always under $50 because they just don't know). My TCU went out while out of town and I went to the junk yard and they sold it for $23. I popped it in, coded it and enjoyed the rest of my trip. With modules these cars are too old to buy new.
I didnt do any readings on voltage yet after i changed charge regulator.
Yes i checked charge history last time before changing charging regulator.
Its not a problem to buy new LM if it will solve this problem.
Maybe im to worrie about buing used LM because i saw this fault on 1/2 LCI E60/61. Better be to get car without this fault and swap LM modules for a try. Then buy new LM.
If the charge histogram looks good, you have a drain somewhere. Does your car go to sleep? Figure out the drain issue or go gung-ho and replace the LM.
10-14-2022, 11:06 PM
Bmw fault: 9cc5 - LM: No message , LIN (RLS)
