robvilla

for the past year my 2004 530i has been in the shop numerous times for the same issue. After awhile of driving my SMG starts to act up. When I say act up, I mean it starts to not respond to certain gears. for example, if I shift from 2nd to 3rd, it will not respond to 3rd and skip to 4th. And if I shift from 4th to 5th it will do the same. Once this happens then I know I only have a matter of a couple miles before it completely fails. Meaning that it will just cycle between Neutral and 1st. I will then have to leave it, usually over night and I can start it up and drive it for about 10-15 miles.

The Indy shop has replaced my pump the first time. Then they replaced the sensor that receives the signal from the shifter. Finally they replaced another sensor that receives the signal from that sensor, which at this point I was sure they were just guessing. They told me that BMW recommended that both parts needed to be replaced in order for the system to function correctly. About 3 months and less than 20,000 miles it is doing the same thing.

When I had it towed back over to the shop, they kept my car for 6 months telling me that the car isn't giving any trouble codes and they think the last thing that needs to be changed is the "Control Unit" which runs about $1200 for the part alone. They said that they didn't want to just change that without know for sure since all the other parts didn't help. They recommended me to take it home a drive it and see if it fails.

I did that and no more than 13 miles later I was stuck a block from my house. I called another Indy shop and told them my issue and they asked me which shop did I take it to so I told him. He told me that he holds that shop in high regards as a reputable shop, which I am not arguing that, I don't think they steered me wrong with most of my experience with them, and said that he can't help me until the car fails and throws some kind of trouble code.

I have been reading many forums saying that it might be the SMG temperature sensor or the HDY Pump sensor, I don't know if those are the same. But one forum said to add a resistor to the HDY Pump sensor. I am really at a lost with this issue. Any help would be great. I really love this car.