Help with Codes and Possible Leads to Problem

[supremexlonly]

Hello!

I have been having a problem with my M5. When turning over, car idles rough, and when driving, I have a surge in RPM which ranges from 2500-5000 rpm. After the surge in RPM, I get the "drivetrain malfunction" light and when I read the codes it had given me the following:

MAP: Stage 2 ACN91 octane (AGG)_1
CODES:
Engine (DME):
21A320-Emergency run 1, coupling from slave: group error-21A360-Emergency operation 3, coupling from slave: group error-21A380-Emergency operation 4, coupling from slave: group error-120918-Boost pressure control 2, shutdown, coupling: pressure build-up blocked-120408-Boost pressure control: shutdown as a follow-up reaction

Engine (DME2):
231501-Error log entry: Send buffer full-21A311-Emergency 1, slave: Group error for DME coupling-21A351-Emergency 3, slave: Group error for DME coupling-21A371-Emergency operation 4, slave: Group error for DME coupling-120418-Boost pressure control, shutdown, coupling: Pressure build-up blocked-CDE413-FlexRay, message (coupling 1 master drive, 41.0.2): missing-CDE433-FlexRay, message (coupling 4 master drive, 61.0.2): missing-CDE436-FlexRay, message (coupling 5 master drive high, 75.0.2): missing-1F0535-Drive, safety function: Master/slave monitoring: FlexRay communication-CDD613-FlexRay, message (wheel torque drive 1, 41.3.4): missing-CDD713-FlexRay, message (wheel torque drive 4, 40.3.4): missing-160021-Crankshaft sensor: general loss of synchronization-160020-crankshaft sensor, signal: implausible-120908-Boost pressure control 2: shutdown as a follow-up reaction

What would likely cause this? Is it a turbo issue? PCV? I am trying to pinpoint so I can order/replace the necessary parts.

Thank you!

[M5Rick]

Where do you start ..
Don't know but I'm thinking check pre-cat and post-cat lambda sensors for some reason, these don't last for ever.

[supremexlonly]

Originally Posted by M5Rick

Where do you start ..
Don't know but I'm thinking check pre-cat and post-cat lambda sensors for some reason, these don't last for ever.

It is a mess... I know the crankshaft sensor replacement will get rid of some of the codes once I get to replace it, but this car has had so many problems recently. Have you had any issues like this?

[M5Rick]

Originally Posted by supremexlonly

It is a mess... I know the crankshaft sensor replacement will get rid of some of the codes once I get to replace it, but this car has had so many problems recently. Have you had any issues like this?

Had mine nearly 8 years now and it's very reliable, I know that putting tunes on these may bring problems so I keep it all stock, it's quick enough for me.
Replace those sensors and see how you go and maybe start removing some of the tune if those codes keep cropping up is what I suggest.

[supremexlonly]

Originally Posted by M5Rick

Had mine nearly 8 years now and it's very reliable, I know that putting tunes on these may bring problems so I keep it all stock, it's quick enough for me.
Replace those sensors and see how you go and maybe start removing some of the tune if those codes keep cropping up is what I suggest.

Oh the car is built, but all my preventative was done, rod bearings, hpfp, good intervals for services. Just after installing the HPFP, injectors, and sparks, I started to really notice it.

The biggest notice I had right before this issue was that the car when I would turn the car over, let it warm up 3-5min, then hit the accelerator, there would be a plume of white smoke that did make it smell like oil…

I have a feeling that the turbos might be going out too. Im almost at 81-83k miles on and been tuned for about the last 20k miles really without issue. Reading from others posts, around 80k is when these start to give out. Hopefully others can chime in too or a tech that could maybe lead me to the right direction 🥹

[M5Rick]

Originally Posted by supremexlonly

Oh the car is built, but all my preventative was done, rod bearings, hpfp, good intervals for services. Just after installing the HPFP, injectors, and sparks, I started to really notice it.

The biggest notice I had right before this issue was that the car when I would turn the car over, let it warm up 3-5min, then hit the accelerator, there would be a plume of white smoke that did make it smell like oil…

I have a feeling that the turbos might be going out too. Im almost at 81-83k miles on and been tuned for about the last 20k miles really without issue. Reading from others posts, around 80k is when these start to give out. Hopefully others can chime in too or a tech that could maybe lead me to the right direction 🥹

It depends how you drive it, if you can cut out the 'digs' then it can go way above 83k. Mines a part daily low miler at 46k now and only gets the occasional WOT.

[supremexlonly]

Originally Posted by M5Rick

It depends how you drive it, if you can cut out the 'digs' then it can go way above 83k. Mines a part daily low miler at 46k now and only gets the occasional WOT.

I think I have only done one launch control, but these cars have such torque it is hard even to do digs without lighting up the tires lol! I got the chance to take it and look more into it and from possible leads, it may be the Camshaft Sensors throwing these codes. Luckily, I will be able to get it out to one of my shops next week and hopefully run a diagnostic on the car. Man, I miss driving this so much 😭

[M5Rick]

Originally Posted by supremexlonly

I think I have only done one launch control, but these cars have such torque it is hard even to do digs without lighting up the tires lol! I got the chance to take it and look more into it and from possible leads, it may be the Camshaft Sensors throwing these codes. Luckily, I will be able to get it out to one of my shops next week and hopefully run a diagnostic on the car. Man, I miss driving this so much ��

You have a 'Competition' also which have quite a few different things from the standard 560's, like the DME's for that extra 15hp.
I personally have never used launch, not in 'dolls house' Britain here where cars are on top of each other and we have more spy cameras watching us than in any other country on earth lol but GL with finding that bug and those cam sensors may be the fly in the ointment holding you up. It's also important to remember not to WOT until oil is at normal temp.

[KurtsM5]

Originally Posted by M5Rick

You have a 'Competition' also which have quite a few different things from the standard 560's, like the DME's for that extra 15hp.
I personally have never used launch, not in 'dolls house' Britain here where cars are on top of each other and we have more spy cameras watching us than in any other country on earth lol but GL with finding that bug and those cam sensors may be the fly in the ointment holding you up. It's also important to remember not to WOT until oil is at normal temp.

I've never seen a need to try launch control either, being the car breaks the tires loose on the 2-3 shift. Launch control should be renamed "Tire Destruction Mode"...

[supremexlonly]

KurtsM5 M5Rick

I was able to get to the car yesterday after all this time, and after removing the skid plate and aluminum splash guard, I found that a tool from the shop was wedged in between which I believe may have been pulling/sitting on top of the wire...

I ended up cleaning the sensor with some MAF cleaner and car runs like a champ!

[KurtsM5]

Originally Posted by supremexlonly

KurtsM5 M5Rick

I was able to get to the car yesterday after all this time, and after removing the skid plate and aluminum splash guard, I found that a tool from the shop was wedged in between which I believe may have been pulling/sitting on top of the wire...

I ended up cleaning the sensor with some MAF cleaner and car runs like a champ!

What the F***??? An Indy, or your tool?

[M5Rick]

Originally Posted by KurtsM5

What the F***??? An Indy, or your tool?

Left his tool behind?...what! the plot thickens

[KurtsM5]

Originally Posted by M5Rick

Left his tool behind?...what! the plot thickens

"which" tool???

[M5Rick]

Originally Posted by KurtsM5

"which" tool???

Some screwdrivers are bendable to reach difficult places, so maybe that

[supremexlonly]

m KurtsM5

When I removed the skid plate and the splash, it just fell out. I have a feeling that it was possibly laid on the harness lol. it wasn't my tool lol but I ain't even mad anymore since MY CAR IS RUNNING!!! But I will say this, this tool was a snap on LOL so I came up!

[KurtsM5]

Did you misspell strap on???