First crack, do the relay, the SMG Fluid (Pentosin) and the Transmission Fluid and see what you get. Much cheaper than a pump and not much more expensive than a salmon relay (a few hundred bucks). May as well reset adaptations at the same time.

There was also some faulty sensor that threw cog lights back when I bought mine ('10). The first test drive it threw the cog light, I told the seller about it, he swapped it, and I haven't seen a cog light again. I'll see if I can dig that up as well.

But the first paragraph is my answer to your direct question.

GL

maw

PS... it was the Gear Position Sensor ... SMG fault position sensor ... search SMG Gear Position here and you'll find plenty.

 

OP I believe maw1124 and mjez are on point with what they've written. I would do fluid changes (i.e. SMG and transmission) first to see if that resolved the problem. The fluids aren't lifetime. If that didn't get me anywhere, then I'd replace the salmon relay. I'd work my way to the more expensive items to replace You also do want to read the specific BMW diagnostic codes. They are going to give you more specific information in which to diagnose the issue. Good luck.

 

Did a transmission fluid change a few days ago (with oil change). Currently waiting on the relay and the smg fluid. Will update you guys once I get them.

 

Also, when I went for an inspection (same place where I did oil change and transmission fluid change), they showed me these pictures (I assume manufacture codes??) and recommended me to change the entire smg pump for $5.6k with labor!! Sounds absolutely crazy to me.

 

Good you did the fluids. Relay next. I keep a couple on hand just because. They are wear items.
After that, it is usually the electric motor for the SMG.
They can be had from Burke Engineering for around 500 USD. The pumps themselves (from what I read) are pretty indestructible. Most places don't know how to troubleshoot just the motor, or do, but ...
I replaced my pentosin, relay, and after the electric motor, my car shifts perfectly. I would not hesitate to drive it anywhere. No resistors, no drug bin relocation, no solenoids. I did score a used pump unit to rebuild just in case.

 

I second this. The Burkhart kit solved my SMG issues and has been good for years now. I also replaced the accumulator for peace of mind.

 

^^^ What's the R&R time for the Burkhart electric motors?

maw

 

Thank you, Burkhart. Also MLR eng have them available.
As for actual time, I am not a Professional. That said I had a little over 5 hours.
I went from the top which means pulling the strut bar, air cleaner and the "manifold" assembly. This took the longest. I also ran the SMG adaptation, which was about 30 minutes. The actual motor swap was under 30 minutes.
I read about doing this under the car. Looking back it may have saved some time.

 

Invest in an INPA cable to read the codes from the SMG computer. As a fellow SMG owner trust me its money well spent.

Salmon relay is good to keep in the car. I swap em out with FCP warranty every so often.

Annually I will remove as much fluid out of the smg reservoir as I can with a fluid pump and fill it with new Pentosin. A true flush would be best.

Bleed SMG via INPA. Do SMG adaptations.

A cog light but with it still working is generally something you want to get ahead of before it leaves you stranded without warning.

Love the SMG, but it does take alot of TLC.

 

Update:
Changed salmon relay but issue still happens. I noticed that it might be the pump not getting enough pressure? When the problem occurs, often times I hear something like a gear cranking noise in first gear/ reverse before it slips back to neutral. Restarting the car again mostly fixes it though. I also checked the smg fluid which was topped out so I think its not about the smg fluid. Im thinking if its the pump itself thats causing the issue or the smg clutch actuator?

 

The SMG fluid is more about quality than quantity. Topping off bad fluid for sale of the car isn't exactly what people are discussing here. So you got some clear fluid in the reservoir and sludge and maybe air gaps everywhere else, like the pump and lines? How do we expect that to work out? Adaptations reset?

maw

 

Noted. Ill try changing the smg fluid as well Just to make sure, can I just extract the smg fluid from the cap on the right side of the engine using a pump and then fill it up with a bottle of Pentosin CHF 11S?

 

I don't think so, but I'm not a wrench. That's one you have a shop do unless you are a shop. They can reset the adaptations as well. I think those processes go hand in hand but don't quote me. That's more important than the relay. Keep your old one in the glove box.

maw

 

Update 4/9/2022
Very late update, I know, but it turns out to be a bad smg unit (
Bought a rebuilt unit and works fine for now!

 

Curious, where did you buy the rebuilt unit from?