why is my m3 stuck on a power loop?

[Hom3less_Trillionaire]

Good evening all, first off happy thanksgiving.
so im having a problem with my e92 m3. for some reason it keeps "power cycling" as I call it. I new I had a bad battery so I replaced that and still have the problem. car turns on fine but just the electrical system keeps cycling. I can rev it but needles won't move, I-drive goes on and off etc. so I looked through the forums and I saw people suggest it might be a bad JBE so I got a new one installed it today and still having the problem. what am I missing? what else could be wrong. I read somewhere that bad throttle actuators can cause the electrical system to go crazy but before I go and spend that money I wanted to get some more help/insight.
you help is much appreciated

[spammysammich]

Originally Posted by Hom3less_Trillionaire

Good evening all, first off happy thanksgiving.
so im having a problem with my e92 m3. for some reason it keeps "power cycling" as I call it. I new I had a bad battery so I replaced that and still have the problem. car turns on fine but just the electrical system keeps cycling. I can rev it but needles won't move, I-drive goes on and off etc. so I looked through the forums and I saw people suggest it might be a bad JBE so I got a new one installed it today and still having the problem. what am I missing? what else could be wrong. I read somewhere that bad throttle actuators can cause the electrical system to go crazy but before I go and spend that money I wanted to get some more help/insight.
you help is much appreciated

Could be something attached to the JBE messing with the CAN bus. What codes are thrown?

[DrFerry]

Wasn't there a recall on the fusebox ground and the battery cable to the fuse box because of similar symptoms. Shake the fusebox a little by bumping and taping it and see if things come back to life. Search the forums using Advanced Search for Fusebox and Battery Cable ground recalls. There's also the RBS (?) batter stabilizer connector (small connector with the blue wire near the battery) that can be problematic if the connection isn't secure, the wires are bad or the RBS itself went south. You're welcome. Good luck.

[Hom3less_Trillionaire]

Originally Posted by spammysammich

Could be something attached to the JBE messing with the CAN bus. What codes are thrown?

I replace the JBE with a new one that I got today. and still having the issue. I use the Carly app (yeah I now its not that great of a scanner ill get my other scanner tomorrow and check ) to check codes and it giving me a bunch of random codes like one that stood out to me was it was saying there was a misfire in 6 out of 8 cylinder. when the car is running fine. ill have to check tomorrow with my other scanner to see what's its throwing.

[Hom3less_Trillionaire]

Originally Posted by DrFerry

Wasn't there a recall on the fusebox ground and the battery cable to the fuse box because of similar symptoms. Shake the fusebox a little by bumping and taping it and see if things come back to life. Search the forums using Advanced Search for Fusebox and Battery Cable ground recalls. There's also the RBS (?) batter stabilizer connector (small connector with the blue wire near the battery) that can be problematic if the connection isn't secure, the wires are bad or the RBS itself went south. You're welcome. Good luck.

I checked BMWs site for a recall put the vin in and it says zero recalls for my car. ill give those a look tomorrow... could it be the battery not being registered ?
I out the new battery and was trying to register it using the Carly app. but ran into error etc. then I cam across a thread on here talking about how they themselves had issues registering batteries using the Carly app. ill try registering it tomorrow using my big scanner and also try out what you suggested and let you guys know.

[DrFerry]

Originally Posted by Hom3less_Trillionaire

I checked BMWs site for a recall put the vin in and it says zero recalls for my car. ill give those a look tomorrow... could it be the battery not being registered ?
I out the new battery and was trying to register it using the Carly app. but ran into error etc. then I cam across a thread on here talking about how they themselves had issues registering batteries using the Carly app. ill try registering it tomorrow using my big scanner and also try out what you suggested and let you guys know.

Not registering the battery just means the alternator is only outputting the amperage required to charge the old battery. IF your new battery has identical specifications then you're okay. However IF your new battery has higher CCA rating then it might not be being charged enough. However, I doubt the problems you described are due to battery registration. A fully charged battery has similar voltage to what's shown in the image below. Anything in the 12.5 to 12.7ish static charge range can cause issues in my own experience. Check the things I previously mentioned.
.

[spammysammich]

Originally Posted by Hom3less_Trillionaire

I checked BMWs site for a recall put the vin in and it says zero recalls for my car. ill give those a look tomorrow... could it be the battery not being registered ?
I out the new battery and was trying to register it using the Carly app. but ran into error etc. then I cam across a thread on here talking about how they themselves had issues registering batteries using the Carly app. ill try registering it tomorrow using my big scanner and also try out what you suggested and let you guys know.

My battery was improperly registered but it never gave me problems. I'm sure the alternator probably got grumpy at some point but the previous owner changed that before he sold to me. I registered my battery just fine with BimmerLink. It had already been coded with bimmercode.

Check all your engine bay grounds and for sure check the fuse box like drferry suggested

[Hom3less_Trillionaire]

Originally Posted by spammysammich

My battery was improperly registered but it never gave me problems. I'm sure the alternator probably got grumpy at some point but the previous owner changed that before he sold to me. I registered my battery just fine with BimmerLink. It had already been coded with bimmercode.

Check all your engine bay grounds and for sure check the fuse box like drferry suggested

so I came across another thread talking about the ground cable. and decided to check it as checking the fuse box and everything turned out fine. still have the problem.i went under the car and took a look at the ground cable. now I dont know if it looks bad or just looks normal due to ware and tare. Ive attached pictures below. hopefully this is the culprit and I can get her up and running. I miss driving her

[spammysammich]

Originally Posted by Hom3less_Trillionaire

so I came across another thread talking about the ground cable. and decided to check it as checking the fuse box and everything turned out fine. still have the problem.i went under the car and took a look at the ground cable. now I dont know if it looks bad or just looks normal due to ware and tare. Ive attached pictures below. hopefully this is the culprit and I can get her up and running. I miss driving her

Attachment 2753581

Attachment 2753582

What codes are being reported?

[irokwrx]

Are your needles jumping around? Is the Idrive screen going in and out? If so tell me do you hear a clicking sound near the fuse box or the trunk? If so report back.

[Hom3less_Trillionaire]

Originally Posted by irokwrx

Are your needles jumping around? Is the Idrive screen going in and out? If so tell me do you hear a clicking sound near the fuse box or the trunk? If so report back.

yeah needles are jumping around and idrive and ac unit goes in and out. I hear a clicking sound by the fuse box

[irokwrx]

Originally Posted by Hom3less_Trillionaire

yeah needles are jumping around and idrive and ac unit goes in and out. I hear a clicking sound by the fuse box

It sounds like a relay. If you can, find the relay that is clicking and pull it out. Then start the car ( the idrive should not flicker or needles should not jump). Replace the relay, if it repeats then there is another electrical issue that need to be sorted. But finding that relay that's clicking is a good place to start. Please report back

[Homeless_Trillionaire]

Originally Posted by irokwrx

It sounds like a relay. If you can, find the relay that is clicking and pull it out. Then start the car ( the idrive should not flicker or needles should not jump). Replace the relay, if it repeats then there is another electrical issue that need to be sorted. But finding that relay that's clicking is a good place to start. Please report back

so I ended up taking it to a shop here in jersey in Jackson nj called TYSpeed. btw great people great Customer service if any only comes across this post for what ever reason and needs help I highly recommend. but anyways I took it to them and Tyler himself worked on my car and took the while front apart and unplugging things one by one to find the problem. turns out it was the MMI prime head-unit thing that I got for CarPlay and backup camera was causing a short thus the car was doing that whole "boot loop" thing to protect that car and other electronics. it has been looog time since I've driven my car and I picked her up yesterday and I was overly excited. I never knew how much I would miss a car

but I want to take the time to thank everyone that helped trying to figure out.

[drwankel]

Interesting conclusion. Having one of those boxes in the system is always suspect when things around it start misbehaving. Good detail to include.