New 4.6is and got a P0741 code
 

Howdy all,

Past week I pulled the trigger on a 03 4.6is, the car was in AZ and I had it shipped up to Denver. I personally didn't look at the car but Danny (who is on here) was gracious enough to take a peek at it for me and it checked out at the time. I took it out for a maiden voyage the other day when about 20 miles in I got the SES light. Driving wise no issue other than a slight harsh downshift from 2-1. I have not tried driving at 65 and letting off the gas to see if RPM's stay or drop yet (just read that today and didn't drive the X). I did notice RPMS were about 2600ish at 65 though no feeling of slipping. I went to O'rileys and used the scanner to reveal a P0741.

One thing that came to mind is my battery is pretty much gone, really rough starts have been the theme for it. Doesn't need a jump but it does not like to start right away. No battery light, but I know that's not how cars should start. I got a new battery I'm going to try and install and see what that may do. I know that these cars hate low voltage and I'm hoping that may be the issue. Another thought is this is a AZ/CA car never been in cold and when I drove it the other day it was a balmy 30 degrees. I was reading about the software update that pertained to harsh downshifts and cold temp. Not sure if this ever had the update or not. Have also read that the Dinan tranny upgrade solved peoples problems. I really hope I'm not going to have to replace a TC right off the bat so wanted to get some thoughts from the experts on here of ideas for what to do.

You can change the battery if its toast thats a good start. but if you clear the code on the trans after the new battery and the code P7041 comes back then you are going to have to think about torque converter replacement and perhaps tranny (harsh 2-1). How many miles are on the X5 that you just purchased?

Thanks for the reply Jay, it has just under 134k. To clear the codes do I need a special scanner? It wouldn't let me do it on the Bosch one from autozone. I was reading that the standard OBD-II scanners don't allow that function on BMW's.

You should check out the scanner that ECS has for the BMWs. Its a Foxwell unit made for ECS (Schwaben). I believe that it can clear the codes that relate to the transmission. I would give them a call and inquire about its depth of operation. Its a pretty decent tool for the low level of investment. I am sure there will be others on this board that will come forth with scanner suggestions for you.

https://www.ecstuning.com/b-schwaben...FQuifgodQ18PdA

When you say that the X5 starts rough what exactly do you mean? Does it turn over slow, etc.?

K, I'll check it out.

It doesn't fire up right away, will crank slowly then start. If took a decent drive yesterday and stopped at the store and after it fired up but I wanted to let it sit for a day to see how it responds. I do know the alternator was replaced recently.

I'd replace the battery for sure, all of these issues point to a bad battery. It was an Arizona/California car so the transition from hot to cold may have just been the final blow to the battery. The battery doesn't have to be fully dead to cause problems.

As for the torque converter code, I'd clear it and see if it comes back. Any code reader should be able to clear the code. I've been using a $20 Autozone code reader for years now. For basic codes it works great, and for more advanced stuff I have INPA/PA Soft. Replacing the transmission fluid and filter might be a good idea as well if it's never been done.

Going to do it this afternoon and hope it fixes it. I'm hoping since it has been sitting for a while that is all it is. I'll try going back and seeing if I can clear it.

Really one the fence about flushing the tranny. On any other car wouldn't even think about it at this mileage but with the mix of people saying it can cause more harm than good kind of unsure what the best route is.

I've changed the transmission fluid on cars with far higher mileage and I've been fine. What I'm proposing isn't really a flush per se, it's just draining the fluid, replacing the filter, and then filling the transmission back up with fresh fluid. You don't get all the fluid out, you get like 60% of it replaced with this method. Then you can do another flush and fill later down the line. It's a much more gentle method as opposed to forcing fluid through the lines under pressure.

I've done this on my 2000 540i Touring at 177k miles, it's now at 184k miles and shifts great. I've also done it on a 1995 750il at 187k miles, it's now at 200k miles with the next owner and drives great. Most recently I did it to a Range Rover at 160k miles, and the current owner is very satisfied with it.

Ok, I gothca. I know it's a debated topic and understand the 2 schools of thought. I would rather swap the fluid but didn't want to create more problems in doing so.

The important thing is to follow the official ZF procedure for filling the transmission. You have to fill the transmission with the engine running at a certain temperature, that's what a lot of people forget to do. The only time I've ever heard of a transmission failing after a fluid change is if the fluid wasn't changed correctly. You also have to use a proper OEM Filtran filter, the aftermarket ones are different internally and can cause a whining sound.

A properly done transmission fluid change will not cause the transmission to fail unless it was going to fail either way. And in a lot of cases it can actually save the transmission from dying. My 1995 750il transmission was awful when I got the car— it whined loudly on cold startup, shifted harshly, and was not smooth at all. It threw a transmission failsafe warning every once in a while too. After I changed the transmission fluid and filter all of the problems went away and it's been running smoothly for the last 12,000 miles with the new owner (who I'm friends with).