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Discussion Starter #1
Posted on this before, hope someone has a Hail Mary, parts replaced, ABS module and multiple reprogram attempts, new battery coded and new alternator and VR. On start up I get the full Xmas tree of warning lights. Idrive won’t come on along with many other things like tilt steering A/C etc. Eventually things come back on after restart car is fine again...sometimes it stalls repeated times and takes me Forever to get it running properly again. I have had some pretty good techs look at it but limited under covid. Anyone have Ista or anything better than Carly in Toronto ? Im
Open to try anything at this point, possible speed sensor ? Too many codes to list. Thanks to this amazing forum in advance. Cheers
 

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I'd still suspect a charging issue. If you have a DMM (or get a $5 one from harbor freight) I'd measure voltage at the underhood terminals before, during and right after you start the car to see what's going on.
 

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Discussion Starter #3
I'd still suspect a charging issue. If you have a DMM (or get a $5 one from harbor freight) I'd measure voltage at the underhood terminals before, during and right after you start the car to see what's going on.
I have a small meter one plugged into the cigarette lighter which because I suspect the same which has shown voltage stability for the most part. I have a multi meter and will start an under the hood voltage investigation. It’s just so random ! Thank you for the suggestion I’ll post back. Wondering if my sprint booster is interfering at all?
 

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Tour booster must be connected to the bonnet terminals, not to the battery so that IBS can register the charge. IBS can be ruined if a charger is connected to the battery directly (so has a reputable BMW tech told me).


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Discussion Starter #6
Thank you for all suggestions. So far direct battery voltage is 12.66 before start, after start 14.16v... under hood voltage reading prestart was 12.64 after start was 14.22. I thought about grounds before but can you please tell me where they are...that would be an awesome help. The sprint or tour booster was installed by a mechanic and I’m not sure but looks like he’s getting the power from wiring below and behind the radio etc. Pls keep the suggestions coming. I will scour the leads on all terminals and connections even thought they are right and clean...it can’t hurt.
 

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Obviously the battery but know there's one on the drivers side exhaust hanger close to the rear sway bar end link. There are a couple in the engine bay but I'll let one of the experts answer that one. You can also run a temporary test wire from the under hood negative terminal to the block just to see if that help's, its worth a try.
 

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Voltage sounds right. But did it act up when you were measuring? You need to get a measurement when all lights come on, etc.
 

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Discussion Starter #9
I will be checking voltage on almost all starts, and then when it acts up I’ll jump out and try to grab another reading. Will clean tighten all cables and nodes and check the grounds that I can find. Anyone know where anymore of the grounds are??? I’ll find and tighten them. It’s an intermittent issue which is why it’s so hard to track down.
 

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Just because it happened to me, the battery posts can be tightened without being properly seated. Loosen the 10mm nut on top and use a socket and hammer to seat the post. My car went dead one day and I found the 10mm nut on the post tight but was able to lift the post right off the battery.

One thing to keep in mine with loose or poor connections is that they may look and measure voltage fine but when you try and pull lots of current they may intermittently fail.
 

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Discussion Starter #11
Ok battery post cleaned, re-seated, ground wire on battery solid and clean. Found the ground on the exhaust hanger driver side will clean and tighten....any other obvious ground wire locations anyone can point out?
 

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There are alot of grounds all over the car, but I doubt that's your issue. Assuming your battery and alternator/voltage regulator stuff is all sorted, you likely have some wiring issues and there is some intermittent short causing your issues. You really need ISTA to do more in depth diagnostics, see which modules are on the same network, etc.
 

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Discussion Starter #13
I guess it’s time for me to get ISTA, I had considered it in the past. What is the easiest way to get all I need to run it. I know I’ll need a laptop and a cable etc. Thanks
 

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Just because it happened to me, the battery posts can be tightened without being properly seated. Loosen the 10mm nut on top and use a socket and hammer to seat the post. My car went dead one day and I found the 10mm nut on the post tight but was able to lift the post right off the batterym.

One thing to keep in mine with loose or poor connections is that they may look and measure voltage fine but when you try and pull lots of current they may intermittently fail.
on my older cars I simply turned on the headlights and other accessories then started motor. If they dim it indicates a high resistance.

Any bad connection would also heat up.

strangely I discovered battery’s with high internal resistance show 12.5 volts but are way short of amps
 

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Discussion Starter #15
Status report! Ista installed and operational. Now can anybody give me a few tips at what to look for when multiple warning lights ...therefore multiple modules have faults. The fault list is longgggggggg. This is my starting point. As before any tips or ideas would help. I will never surrender !
941119
 

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Clear them and see what comes back. Then post a screenshot of the codes. Electrical problems produce an unreasonably large amount of faults on this car, ask me how I know.
 

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I am with you on that
When I got my low priced 530xi
It had 18 faults per Carly, cleared them , only 3 faults came back
 

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Discussion Starter #19
Faults cleared and Voila, DSC module can not communicate, this is what I suspected. So a few years ago I had the ABS module replaced or the DSC, mechanic may have been using slang calling both the same thing...if that makes sense. I’ll try to find my bill but recall it being 4000 under lubrico,
941137
F562EE4F-BE46-4341-8198-83149737F51A.jpeg
941138
F562EE4F-BE46-4341-8198-83149737F51A.jpeg
3ED20353-61B1-4699-A36F-A7539C9D4794.jpeg
Anyway it doesn’t seem to be a pump error or a speed sensor or steering angle sensor. It seem strictly a comm issue, I recently had the ABS/DSC module reprogrammed and I’m still left in this situation. Suggestions on how to proceed ? Thanks in advance
 

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When you’re reading these codes, is the key in accessory mode, on with engine off, or key on engine on? I think I’ve had a DSC error when I read codes in accessory, which makes sense because there is no power to the DSC module when that’s the state. A lot of the other modules are also off too so you won’t get codes.
Run it with engine on and then you may get codes from the DME, since it seems like you had other issues.
 
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