Drivetrain Malf, Limp mode, then Engine off...

bongshi4 · 11-10-2021, 08:16 AM

Guys,

Need your guide here...

I have 2014 f10 M5 (60,000km), BM3 stage 1 91oct (with no cold start), PG intake, Akra exhaust.

First, for the background history, I don't drive this car daily and only drive 50~100km during weekend.
Most of time, M5 is parked at indoor parking lot without power supply.
Meaning, my battery condition is quite bad since it has never been replaced.

The first drivetrain malfunction warning came up about last week, during the cold engine start up after 30~40mins of joyful driving from last day.
But it disappeared after few seconds, and when I have checked the fault code history using ISTA, I found 'rail pressure sensor 2: short circuit to ground' which is not active anymore.

Article from bmw says the sensor does not tend to fail easily, just need plug/unplug the sensor on fuel rail bank 2.
But due to the access of the sensor, I haven't done it yet...

Today,
After the cold start up, about 3~5 min after the ignition, DT malfunction warning came up again and disappeared, I thought it was same issue.. so I kept driving.
About 5mins of driving, I had limp mode warning...
Few seconds later, Engine stopped itself and gear went to Neutral.
I was able to restart the engine, and drove about 100meter to park the car safely.

Hah.....
I was so worried since I've seen many seized engine post with f10 m5...

Luckily, there was no abnormal sound from engine bay such as metal striking.

One of my friend suggested to replace the battery with new one, since the low battery could result low performance of ignition coils.. (maybe?!!)
And remove the cold start delete, since malfunction warning comes up during or right after the cold start up.

Those two are done!

So.. Did anyone experience such problem before due to the low battery?
Or is the BM3 culprit?

M5Rick · 11-10-2021, 11:14 AM

Have you a trickle charger with an accessible power point close by, these can be charged on the engine bay points with the bonnet shut and car locked.

m5rosco · 11-10-2021, 05:15 PM

When were the spark plugs and coil packs last changed? The DTM warning is normally a result of a misfire.

bongshi4 · 11-10-2021, 06:47 PM

Quote:

Originally Posted by M5Rick

Have you a trickle charger with an accessible power point close by, these can be charged on the engine bay points with the bonnet shut and car locked.

Yes, I have done that using CTEK charger.
But even after the full charge, I was getting low battery alarm a week after

bongshi4 · 11-10-2021, 06:49 PM

Quote:

Originally Posted by m5rosco

When were the spark plugs and coil packs last changed? The DTM warning is normally a result of a misfire.

Spark plugs were replaced at 55k km, but coils haven't been replaced yet.
Maybe it is time to check the coils.

However, if I have any misfire, it should be logged on fault history so I can see those via ISTA, right?

M5Rick · 11-11-2021, 02:32 AM

Quote:

Originally Posted by bongshi4

Yes, I have done that using CTEK charger.
But even after the full charge, I was getting low battery alarm a week after

Were you actually getting the six yellows and green light at the end of the charge scale on the CTeK, but even after charge a spent battery may go quickly after a week and I would have thought if it's weak then it wouldn't complete the charging cycle.

vafan13 · 11-11-2021, 07:37 AM

Quote:

Originally Posted by bongshi4

One of my friend suggested to replace the battery with new one, since the low battery could result low performance of ignition coils.. (maybe?!!)
And remove the cold start delete, since malfunction warning comes up during or right after the cold start up.

Those two are done!

So.. Did anyone experience such problem before due to the low battery?
Or is the BM3 culprit?

If I'm reading correctly, the OP already replaced the battery. Has the issue since gone away?

Not sure if someone has experienced your exact issues as a result of it, but low battery seems to cause all kinds of random gremlins to pop up on this car.

M5Rick · 11-11-2021, 07:45 AM

Aha I missed that bit about the new battery.

M5Rick · 11-11-2021, 10:59 AM

Quote:

Originally Posted by bongshi4

Yes, I have done that using CTEK charger.
But even after the full charge, I was getting low battery alarm a week after

I carry a new spare ignition coil in the car, what you could do is purchase one and swap them around one at a time with the new one to see if one of the coils is failing on yours.

INFURNO · 11-11-2021, 11:20 AM

Error says you have a short. Could be the sensor or somewhere else. The rest of what you said sounds plausible synonyms of a short. Get BM3 off just to eliminate a factor. Go back over any modifications you've made and anything you touched. Check for any tools left behind and check all the connections. Check cables for damage. Don't drive the car until this is resolved since it's possible you could do more damage. Or even end up with a fire.

Car was fine for 60k km. It's likely this is the result of some recent work.

11-10-2021, 08:16 AM	#1
bongshi4 New Member 25 Rep 28 Posts Drives: 2014 F10 M5 Join Date: Dec 2018 Location: South Korea iTrader: (0)	Drivetrain Malf, Limp mode, then Engine off... Guys, Need your guide here... I have 2014 f10 M5 (60,000km), BM3 stage 1 91oct (with no cold start), PG intake, Akra exhaust. First, for the background history, I don't drive this car daily and only drive 50~100km during weekend. Most of time, M5 is parked at indoor parking lot without power supply. Meaning, my battery condition is quite bad since it has never been replaced. The first drivetrain malfunction warning came up about last week, during the cold engine start up after 30~40mins of joyful driving from last day. But it disappeared after few seconds, and when I have checked the fault code history using ISTA, I found 'rail pressure sensor 2: short circuit to ground' which is not active anymore. Article from bmw says the sensor does not tend to fail easily, just need plug/unplug the sensor on fuel rail bank 2. But due to the access of the sensor, I haven't done it yet... Today, After the cold start up, about 3~5 min after the ignition, DT malfunction warning came up again and disappeared, I thought it was same issue.. so I kept driving. About 5mins of driving, I had limp mode warning... Few seconds later, Engine stopped itself and gear went to Neutral. I was able to restart the engine, and drove about 100meter to park the car safely. Hah..... I was so worried since I've seen many seized engine post with f10 m5... Luckily, there was no abnormal sound from engine bay such as metal striking. One of my friend suggested to replace the battery with new one, since the low battery could result low performance of ignition coils.. (maybe?!!) And remove the cold start delete, since malfunction warning comes up during or right after the cold start up. Those two are done! So.. Did anyone experience such problem before due to the low battery? Or is the BM3 culprit?
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11-10-2021, 11:14 AM	#2
M5Rick General 60089 Rep 19,556 Posts Drives: M5 F10 DCT Gunmetal Join Date: Aug 2018 Location: Southern England iTrader: (0)	Have you a trickle charger with an accessible power point close by, these can be charged on the engine bay points with the bonnet shut and car locked.
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11-10-2021, 05:15 PM	#3
m5rosco Second Lieutenant 211 Rep 250 Posts Drives: 2016 F10 M5 Join Date: Jun 2020 Location: UK iTrader: (0)	When were the spark plugs and coil packs last changed? The DTM warning is normally a result of a misfire.
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11-11-2021, 07:45 AM	#8
M5Rick General 60089 Rep 19,556 Posts Drives: M5 F10 DCT Gunmetal Join Date: Aug 2018 Location: Southern England iTrader: (0)	Aha I missed that bit about the new battery.
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11-11-2021, 11:20 AM	#10
INFURNO Private First Class 167 Rep 191 Posts Drives: F10 M5 Join Date: Oct 2010 Location: WA iTrader: (0)	Error says you have a short. Could be the sensor or somewhere else. The rest of what you said sounds plausible synonyms of a short. Get BM3 off just to eliminate a factor. Go back over any modifications you've made and anything you touched. Check for any tools left behind and check all the connections. Check cables for damage. Don't drive the car until this is resolved since it's possible you could do more damage. Or even end up with a fire. Car was fine for 60k km. It's likely this is the result of some recent work.
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