[hi rpm]

E92 335xi has intermittent slow crank, twice in a week it's stopped briefly before cranking more.

Checking voltages I have (typical values)

Multimeter:
12.05 after sitting overnight, at engine bay terminals.
13.25-13.6 engine running, at terminals.
14.5 engine running, between alternator positive cable connection and alternator body.
12.4 right after shutting car off at engine bay terminals.

Cheap lighter socket voltmeter:
12.05 off after sitting.
12.4 off after running.
12.8-13.35 engine running; driving, various acc's on/off.
Dips lower when cranking, saw 9.xx once.

Sometimes it fires right up reading 12.05 volts.

Battery about 3 years old, the largest diehard gold.

2 years ago, replaced driver side ground strap with a battery cable and spliced a new end section of the positive starter-alternator cable that crosses over the engine. (Both corroded.) Started great for 2 years after.
I noticed that postive cable gets too hot to hold before the engine is warm, so my guess is there's an issue with it.

Ideas/advice welcome.

P.S. Is there a good way to connect a jumper from the alternator positive to the positive terminal, in parallel with the battery-starter-alternator cable?

[fastboatster]

might be your starter going out. had something very similar, had to use my jump pack a couple of times and then finally, after a short while, it wouldn't crank at all. how many miles does your car have? yes, also check the resistance of that positive cable.

[hi rpm]

Originally Posted by fastboatster

might be your starter going out. had something very similar, had to use my jump pack a couple of times and then finally, after a short while, it wouldn't crank at all. how many miles does your car have? yes, also check the resistance of that positive cable.

82k mi. Can the resistance of that cable be measured on car? Assume it's supposed to be the least resistance path between alternator and pos terminal...Should it be close to 0 ohms?

[fastboatster]

Originally Posted by hi rpm

82k mi. Can the resistance of that cable be measured on car? Assume it's supposed to be the least resistance path between alternator and pos terminal...Should it be close to 0 ohms?

probably slightly larger but probably on the order of a few ohms, but I don't know that. probably would be good to measure that resistance with battery disconnected. My starter quit at 133kmiles (2009 328i), your mileage may vary, though. I am just spitballing here, some people with ISTA installed might post in this thread later with more systematic way to troubleshoot your problem, I tend to shoot the parts cannon too much

[wrevilo]

HPFP can cause starting issues also. I had cold start long cranks, which was one of the ways that helped diagnose that I needed to replace mine.

[hi rpm]

Originally Posted by wrevilo

HPFP can cause starting issues also. I had cold start long cranks, which was one of the ways that helped diagnose that I needed to replace mine.

I've been wrong before but I can't imagine that would actually cause the starter to stop cranking, which has happened twice here.

[gbalthrop]

Originally Posted by hi rpm

E92 335xi has intermittent slow crank, twice in a week it's stopped briefly before cranking more.
Checking voltages ...typical values)
12.05 after sitting overnight, at engine bay terminals.
13.25-13.6 engine running, at terminals.
14.5 engine running, between alternator positive cable connection and alternator body.
12.4 right after shutting car off at engine bay terminals.
Cheap lighter socket voltmeter:
12.05 off after sitting.
12.4 off after running.
12.8-13.35 engine running; driving, various acc's on/off.
Dips lower when cranking, saw 9.xx once.
[Those Voltage values, & reported intermittent slow crank, suggest an issue in the Alternator B+ wire (LARGE Red wire between Alternator & Jumpstart Terminal). ALL voltages are LOW except 14.5V at Alternator. Your battery is NOT being properly charged when engine running. Voltage drop of 2.0V to 2.5V is NORMAL during starter cranking.]
... 2 years ago, replaced driver side ground strap with a battery cable and spliced a new end section of the positive starter-alternator cable that crosses over the engine. (Both corroded.) Started great for 2 years after.
I noticed that postive cable gets too hot to hold before the engine is warm, so my guess is there's an issue with it.
P.S. Is there a good way to connect a jumper from the alternator positive to the positive terminal, in parallel with the battery-starter-alternator cable? [YES, VERY Carefully ]

It appears that you have correctly Identified the wiring fault, namely the Large B+ Cable that runs between the Alternator & Jumpstart Terminal. Here is RealOEM.com diagram:
https://www.realoem.com/bmw/enUS/sho...diagId=12_1339

Cable Heat, as well as voltage readings, suggest that. I presume the REASON you spliced/crimped NEW End Section onto that cable before was similar crank/charge issue? There have been other reported cases of that cable coming completely loose from End Crimp Connector, or breaking at that connector.

While that B+ Cable is the most likely suspect, ANY loose or corroded wiring or connectors can cause your symptoms, from:
1) Battery to Jumpstart Terminal, including Transfer Point at front of battery;
2) B+ Cable from Jumpstart Terminal to Starter;
3) Alternator Branch of that B+ Cable;
4) Primary Engine Ground Strap at Starter;
5) Loose Battery Terminal;

Your Voltage Readings, taken together with Intermittent slow/suspended Starter Crank, suggest an issue in B+ Cable at a point that affects BOTH Alternator Output Voltage to Jumpstart Terminal, AND Battery Voltage Supply to Starter Motor. But AT LEAST there SHOULD be higher Voltage readings (> 14.0V) measured at JS Terminal & Lighter Socket with engine running.
George

[hi rpm]

Originally Posted by gbalthrop

...Your Voltage Readings, taken together with Intermittent slow/suspended Starter Crank, suggest an issue in B+ Cable at a point that affects BOTH Alternator Output Voltage to Jumpstart Terminal, AND Battery Voltage Supply to Starter Motor. But AT LEAST there SHOULD be higher Voltage readings (> 14.0V) measured at JS Terminal & Lighter Socket with engine running.
George

Thanks. I felt the cable again this morning about a minute after starting and it was pretty warm--warmer in the original aluminum wired section than the splice. Valve cover cold. (And yes, the reason for the splice was the crimp end falling apart and causing poor cranking.)

I better replace it.

[marvinstockman]

Check you multimeter on another vehicle.

[hi rpm]

It was the cable. Got worse before I got the part so I cut a section out and respliced it, lighter voltage went from max 13.5 to max 14.7. The wire end or crimp must have gone bad in an invisible way.

Barely related but I had to jump the car and blew the footwell module, so fml and be careful.

[gbalthrop]

Originally Posted by hi rpm

It was the cable... I had to jump the car and blew the footwell module, so fml and be careful.

Glad to know you correctly identified the Cause. Sorry to hear about the FRM. Sure it wasn't one or more of the 4 FRM Fuses: F41,F81,F84,F86 on 2008 & later?

"fml" reminds me of the NYC Trial: "DJT, This is Your Life"
For those (MOST) of you who are too young to remember that TV Series:
https://www.google.com/search?q=this...hrome&ie=UTF-8
George

[hi rpm]

Originally Posted by gbalthrop

Glad to know you correctly identified the Cause. Sorry to hear about the FRM. Sure it wasn't one or more of the 4 FRM Fuses: F41,F81,F84,F86 on 2008 & later?

Nope, guess I better check them. I should be so lucky that it's multiple fuses instead of a $$$ repair. But the headlights are messed up, no dash lights, no turn signal, no windows, no seatbelt handoff.

[hi rpm]

Originally Posted by gbalthrop

Glad to know you correctly identified the Cause. Sorry to hear about the FRM. Sure it wasn't one or more of the 4 FRM Fuses: F41,F81,F84,F86 on 2008 & later?

"fml" reminds me of the NYC Trial: "DJT, This is Your Life"
For those (MOST) of you who are too young to remember that TV Series:
https://www.google.com/search?q=this...hrome&ie=UTF-8
George

Naturally the fuses were fine. If you or someone in this thread is an expert amateur coder, I'm having issues trying to set the new (used) module up. If not that's fine.

It's the same part number and from the same model, so based on what people said when they put used ones in, I thought at least some functions would return. No, so my money's on a bad module and I wonder how many times it's been sold and returned...But I'm not sure yet.

I have a JB4 set to map 0,
Bimmergeeks K DCan cable,
Port set to COM1 with 1 latency,
and "easybmwtools" package installed on Win11. It's not easy.

INPA never says ignition is on even with engine running. When trying to access the FRM it says "Datatransmission to controlunit disturbed" and stops. It will access some modules and provide info; others it will say something like XXX not there, YYY is there so I probably don't have them.

WinKFP, Entered VIN, clicked on Update ZUSB, ECU family blank, Integration position blank. I think they need car data files installed somewhere but I thought "easybmwtools" was supposed to do that. Maybe something went wrong with installation.

I didn't try NCS Expert yet and I think I'm done for today.

[gbalthrop]

Originally Posted by hi rpm

Bimmergeeks K DCan cable, Port set to COM1 with 1 latency, and "easybmwtools" package installed on Win11.
It's not easy.

INPA never says ignition is on even with engine running. [Later Models such as yours had NO Ignition On Signal.]
When trying to access the FRM it says "Datatransmission to controlunit disturbed" and stops. It will access some
modules and provide info; others it will say something like XXX not there, YYY is there so I probably don't have them...

Attached is ISTA ScreenPrint of your OBD II Socket wiring. Note that on your 2013 model, there is NO "Ignition On"/ KL15 wire.
On my 3/2007 build N52K, there is such a KL15 wire at Pin #1, but apparently on your 2013, there is NO metal socket at Pin #1,
bottom Outboard Socket.
As I understand your post, you ARE able to connect to some Modules, so the Cable & your installation are Working.

When you try to connect to a particular module & get error message: Module "A" NOT found; found Module "B" (Gefunden),
that means you MAY need to select (or add) a different "SGBD" or Variant of that module to your "Script Selection Box"
where you select functions. I can provide a pdf on HOW to do that. FIRST though, please review the attached pdf:
"INPA Tutorial Quickstart" and then run "Functional Jobs" and:

1) View, Save, Attach a ScreenPrint of "F2 > Identification".
That Screen shows, in Column #4, the SGBD or Variant of EACH Module in your Vehicle. We can then determine what
modifications of your Script Selection Box may be required, or if your Datens files contain program files for those Late
Model variants.

2) While there in "Functional Jobs", View, Save, Attach ScreenPrints (2 pages) of FJ > F4 > F1 Read Error Memory, ALL Modules.

3) Please ALSO attach a ScreenPrint of any Error Message you get when trying to connect to the FRM.
George

[hi rpm]

Originally Posted by gbalthrop

Note that on your 2013 model, there is NO "Ignition On"/ KL15 wire...

Thanks; I'm amazed I didn't hear that looking up a hundred things. In the meantime I replaced the easybmwtools install with Bimmergeeks Standard Tools and downloaded a Daten file. (I don't know if BG is better but the former was advertised as being standalone, which didn't work.) Next step I believe is to use the Coding Tool to install the Daten. Assuming the module remains dysfunctional after a cursory retry, I'll follow your steps and post again in about a day.

[hi rpm]

Ok, retry failed, so I took the screenshots. Messing around in INPA later I hit Ident when already in Ident and got a longer list so I saved that too as Identification 2.

WinKFP error when trying to update module also saved.

My Daten file is E89 v70 by the way.

(Edit: 2nd FRM acts the same as the 1st, lights always on and brake lights work but that's about it.)

[n54335i02121997]

There is a ground strap on the back right of the vehicle. Remove the passenger rear wheel and inspect. I have seen that overlooked before. Guy's voltage would drop almost immediately whenever he hooked up the battery. Sometimes it would start, other times it would crank extremely slowly. Sometimes it literally would not charge the car.

Worth a look, especially if you have rapidly shifting voltages.


Edit: Shit, I did not see that was already suggested and the issue was solved lol. My bad

[hi rpm]

Originally Posted by gbalthrop

...3) Please ALSO attach a ScreenPrint of any Error Message you get when trying to connect to the FRM.
George

If you have insight on the screenshots two posts above this one please let me know! I feel pretty sure the module is faulty but I'm no expert.