[alexng72]

Hi guys,
So my girlfriend's car has a very rough idle and it feels like misfiring but when i scanned the car it showed these coded. It happens after I changed the serpentine belt for her. Any ideas would help? Thank you!

[John H.]

Does it lope when starting up cold? The symptoms are when engine cold or at operating temp?

[alexng72]

Originally Posted by John H.

Does it lope when starting up cold? The symptoms are when engine cold or at operating temp?

It only happens when cold start

[Kwood-F10-535i]

You should use ISTA to run the BMW diagnostics. The general code reader is not much help on these cars. Too many non standard PGN's

[alexng72]

Originally Posted by Kwood-F10-535i

You should use ISTA to run the BMW diagnostics. The general code reader is not much help on these cars. Too many non standard PGN's

Yea I'm gonna take it to my indy shop for them to look at it. I just tried to identify the issue but it seemed more complicated than i thought.

[Kwood-F10-535i]

Originally Posted by alexng72

Yea I'm gonna take it to my indy shop for them to look at it. I just tried to identify the issue but it seemed more complicated than i thought.

Ya unfortunately these cars are so complex that the general fault codes really just end up confusing you more. You should look into getting ISTA, and ESYS for yourself. Save a bunch of money (Software is free if you ask the right people on here.) It works on all BMW models including the new G-Series. It will literally run a full car self test and identify errors you may not even know you have.

[alexng72]

Originally Posted by Kwood-F10-535i

Ya unfortunately these cars are so complex that the general fault codes really just end up confusing you more. You should look into getting ISTA, and ESYS for yourself. Save a bunch of money (Software is free if you ask the right people on here.) It works on all BMW models including the new G-Series. It will literally run a full car self test and identify errors you may not even know you have.

I definitely will give it a try later today. Thanks for your advice!

[NasN55]

Originally Posted by alexng72

I definitely will give it a try later today. Thanks for your advice!

It could be carbon buildup on the valves. Consider walnut blasting or seafoam through an intake vacuum line.

[alexng72]

So i took the car to an indy shop. They diagnosed it and turned out there was a missing fuse for a dtml pump. They put the fuse in there and everything works perfectly now. I was surprised that I never touched the fuse box before and don't know how it missing a fuse. Glad that it didn't cost anything to fix it. It's just weird haha

[philipm785]

Great outcome!

[alexng72]

Originally Posted by philipm785

Great outcome!

Yeah man inwas so surprised when the tech called me about it. I mean if there was a missing fuse, why didn't it happen before but till last week. He said he couldn't find any fuses that flew out if the fuse box or anything. Just a missing one in the fuse box. 🤷*♂️

[ezaircon4jc]

Originally Posted by alexng72

So i took the car to an indy shop. They diagnosed it and turned out there was a missing fuse for a dtml pump. They put the fuse in there and everything works perfectly now. I was surprised that I never touched the fuse box before and don't know how it missing a fuse. Glad that it didn't cost anything to fix it. It's just weird haha

So, assuming she isn't the original owner, the previous owner pulled the fuse; wonder why??? I foresee a CEL in her future.

Here's something I found about the DTML pump.