Transmission Malfunction Came and Went Away!!
 

So, for the 1st time at 108900 miles, I experienced the Transmission Malfunction/ Reduced Power warning on my way home 2 days ago. The car won't go above 30MPH, and the RPM would only go up if I stepped on the gas. When I started the car in the morning, it was the same thing. Called my Indy and told him I will be there after work. But the warning went away when I started the car after work! I drove to the Indy and he hooked up his computer, but he said it gave him error code 51A6 and 3 other non related codes about the engine and ABS (I'm overdue for the ABS flush). None of the 2 infamous Transmission error codes!

The only thing that he suggested is that I replace the Crankshaft Positioning Sensor at this point, saying that it's normal to change it for these cars at this mileage, I am thinking that the transmission malfunction warning will come back and I will have to spend the money to replace the suggested components.

Should I start by changing the CPS? Your expert suggestion is appreciated, please. Thanks.

All I can say is I have a 2009 535 and I certainly do not intend to replace my CPS unless it fails. I acknowledge that if it fails the engine won't start, but I can't even begin to list the other items that would do the same... (for fun: starter, relays, fuses, start button, CAS, dme, fuel pump, clutch switch, battery) and I don't intend to spontaneously replace any of these just because of the car's age. Heck, there is no guarantee that a new one of any of these parts won't fail either.

....and it is back! Had a hard time starting the car and ofcourse started in limping mode showing the Engine Malfunction Reduced power/ Malfunction in Transmission warning and images.

Will limp to the Indy shop in the morning. With my luck, it might be gone in the morning showing the 51A6 code again!

https://cimg9.ibsrv.net/gimg/5series...3148dcc16.jpeg
https://cimg1.ibsrv.net/gimg/5series...9d7cc1cbb.jpeg
https://cimg2.ibsrv.net/gimg/5series...aaf9e0101.jpeg
https://cimg6.ibsrv.net/gimg/5series...b86623ba7.jpeg

UPDATE: Indy, who I'm going to for a while now, is confident that the issue is with the Crankshaft Positioning Sensor. He thinks that it is too early to have that Transmission Issue, and it will clear once he replaces the sensor and clears all the codes.

Sas anyone in the DFW area gone through the Transmission Fluid/ Filter/ Solenoid replacement?

UPDATE 2: Indy was right. He replaced the CPS and cleared the error codes. Today is the 3rd day that I'm driving the car, and everything seems to be back to normal. There was no actual transmission issue, just an erroneous code thrown from the faulty Crankshaft Position Sensor!

Time to do the brake fluid flush. Indy reported 20% left on the rear brake pads. He suggested to wait and do the flush at the same time of the brake job in 2/3 months.

Just wanted to see if anyone went through the transmission ordeal of replacing the fluid/ filter/ solenoids replacement in the DFW area, and which shop they used.

Bumping this thread to add my own take. I had similar issues on my '07 525xi, and it turned out to be a bad CPS sending erroneous signals, which the other modules (including the transmission circuit) couldn't understand, throwing a metric crap-ton of other codes.
Part 1: https://5series.net/forums/e60-discu...estion-151260/
Part 2: https://5series.net/forums/e60-discu...ervice-151328/

My vehicle is now at 119,850 and I just took it for an Oil Change and check up. My Indy highly suggested that I do a Transmission Fluid and Filter/ Oil Pan/ Gasket (single part) change, which I went ahead and did too along with changing the Air Filter and Cabin Filters. Damage: $640!!

My indy mechanic says my oil pan gasket needs to be replaced too ($840) but many years later, I still haven't gotten it done. My car isn't throwing malfunction notifications though..

So mid December 2023 my gears started lagging when going from 1st to 2nd to 3rd, and a couple days later I get a transmission malfunction. The next day I throw my code reader in the car, and I get 27 error codes. I have another BMW, so I left it until yesterday February 22 to get it towed to the dealership. I haven't touched the car nor started it in a month and a half. I start the car to get it ready for the tow, no transmission snowflake, no check engine light, nothing. I drive it around the block 5 times. Nothing. It wasn't even lagging between gears. I had it towed to my dealership anyway, and told them what happened. 27 codes disappeared though. What in the heck? I'm thinking it's a sensor too, and hoping it's not a failing transmission, but this is my daily driver, and it's got 160k miles on it, and I do beat it to death, so we'll see what they say. How has your car been since the crank shift sensor was replaced?