Help needed
Thread Starter
Heel & Toe
Joined: Jan 2022
Posts: 24
Likes: 0
From: Ohio
Help needed
Alright guys I need some help I have a 2016 m7 z51 with 41k miles I just bought the car a month ago and there is some electrical issues with the car and was wanting to get outside opinions on what you think it might be. First off I can get in the car sometimes and start it and start driving and the dash radio and hvac will shut down for a split second and come back on and from what I can gather I think it’s voltage related because it only does it when the volt meter on the dash gets to 15volts or above. I just put a brand new battery in it and that didn’t fix it. Could it be body control module related? Now to the second issue I get in the car a lot of times and only the driver dash and door speaker is working. I can move the tone settings to other speakers and no sound comes out My phone connects to the car just fine but if some calls I can’t hear them through the speakers but I got in yesterday while I was on a call and it connected to the car and I could hear them through the speakers and all the speakers was working I checked them with the fade and balance. Got in to to car today and back to just the driver speaker working fade and balance is centered. I’m lost as to what might be causing this. I would greatly appreciate any feedback. Thanks
Tech Contributor
Joined: Oct 1999
Posts: 41,066
Likes: 9,833
From: Charlotte, NC (formerly Endicott, NY)
It would help if you can get a scan run on the entertainment system. However, you will need a scanner equivalent to the GM MDI unit used by the dealers. There are a fair number of diagnostic codes that can be generated by the system that may help isolate the problems. The codes won't tell you what to fix but where to look for a problem.
I suspect the issue is at the head end of the entertainment system as you have proven to yourself that all of the speakers work under the right condition. That means it has to be a control element that isn't working correctly. One other thing that you should know. Generator output voltages of 15.5V are considered normal operation.
Bill
I suspect the issue is at the head end of the entertainment system as you have proven to yourself that all of the speakers work under the right condition. That means it has to be a control element that isn't working correctly. One other thing that you should know. Generator output voltages of 15.5V are considered normal operation.
Bill
Roadster Madness. 😠
Joined: Sep 2009
Posts: 6,304
Likes: 2,372
From: Ventura Co Ca
SoCal Regional Events Coordinator
St. Jude Donor '13, '20-'21
I think the first thing I would do is check and make sure the battery connections are tight! I had that happen one time and the problems went away.
The second thing I would try is disconnecting the battery for 15-20 minutes and tighten it up again! Just a thought.
The second thing I would try is disconnecting the battery for 15-20 minutes and tighten it up again! Just a thought.
Thread Starter
Heel & Toe
Joined: Jan 2022
Posts: 24
Likes: 0
From: Ohio
Im almost wondering if it could be a bad ground somewhere for the dash and hvac shutting off I went out and got on it pretty hard and it started cutting the gauges off. If I rev the engine sitting parked it does it too sometimes. Does anyone know if there is a schematic of all the grounding points?
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Racer
Joined: Mar 2016
Posts: 442
Likes: 157
From: Sayre PA
Definitely some kind of intermittent connection issue. Could be a lot of time to find this. I wouldn't be surprised if the car has a prior history of trying to fix the problem. Unlikely to be a defective module, the problem would not correct itself.
Thread Starter
Heel & Toe
Joined: Jan 2022
Posts: 24
Likes: 0
From: Ohio
So I found if I am on a FaceTime call when I get in the car my phone connects and all the speakers work and I can. Hear the person through the speakers and talk to them through the car but if I get in normal and start the car only the driver speakers work and then if I try to call someone I can’t hear them through the speaker but it does show I’m on a connected call on the dash. But it doesn’t work every time I get in the car.
Last edited by shaas07; Jan 12, 2022 at 10:18 PM.