“Transmission Malfunction” 2009 750Li

[Rand Man]

Hey, I’m back in the BMW game. I’ve had a 1980 320i and a 1990 318i. Yesterday I stepped up to the 7 series. Today, I am dead in the water. Try to start: I’m not actually sure it started. There’s some noise, maybe just the fan. Shifter will not move out of Park. Steering wheel does not turn. Dash says Transmission Malfunction.

Somebody please tell me there is a simple fix. I just laid down a wad of cash and now the wife ain’t happy. Hopefully, there are already threads about this, but I haven’t posted here in several years.

[Rand Man]

I went and got my old junk car. Got home and the Bimmer started. All I did differently was to press a button on the key fob (looks like a star??). Should have tried that before. I will go back out there and check the fluid after while.

[328 Power 04]

That car needs a full diagnosis of all the modules. That event will have been stored. It will do it again.
That kind of car requires diag tools.

[bmwdirtracer]

I hate to be the bearer of bad news, but this car is NOT a good buy - at any price. This is the worst engine BMW's ever made - in it's very first, most unreliable , year. And the first year of a new flagship model - also the least reliable. BMW has been fighting, and losing, one class-action lawsuit after another over this engine.

Timing chains, valve guide seals, mass airflow sensors, oil consumption, battery/alternator charging, all the plastic pipes and hoses on top of the motor failing....the list goes on and on.

If there's any hope of backing out of your deal, do it now, and get yourself a good six cylinder BMW.

You won't be checking the transmission fluid, unless you're going to be lying on the ground under the car with the engine running. But, not to worry....as Abel points out, step 1 is reading the codes in every computer with a quality BMW specific scan tool.

My sincere apologies for being so harsh, but I'm seriously trying to convey the horrific failure rate of this car.

[Rand Man]

I hate to be the bearer of bad news, but this car is NOT a good buy

My sincere apologies for being so harsh, but I'm seriously trying to convey the horrific failure rate of this car.

I thought the F01 was a better car then it’s predecessor.

[bmwdirtracer]

https://www.eeuroparts.com/blog/bmw-...e-hot-garbage/
https://bmwtuning.co/n63-engine-problems/
https://thelemonfirm.com/2019/12/03/...ed-n63-engine/
https://thelemonfirm.com/2021/08/17/...tion-lawsuits/
https://static.nhtsa.gov/odi/tsbs/20...63026-9999.pdf

et al.

[Rand Man]

I took it to a shop. Said I have code 400626. Said I need a new transmission. I read somewhere this could be a bad connection on the controller. Is there any truth to that?

[Rand Man]

Also, does anyone know how much transmission fluid this thing is supposed to hold. I understand there is a drain plug and a fill plug. You just fill till it runs out the fill plug???

[bmwdirtracer]

It is certainly worth checking the round connector on the transmission for fluid wetness. Neither I nor any tech I know has memorized all the codes of a (semi) modern BMW.....you're going to need to provide the written code description as given by the scan tool.

And I'd also suggest that you take the car to a BMW shop that has ISTA, and let them run the test plan for your code(s). I recently installed a BMW supplied new (reman) transmission in a very similar car to yours; the bill ran about $6500 as I recall. Maybe you've just got a shifter malfunction....it's worth the price of ISTA testing to make sure. Failure to shift out of park is not a common symptom of trans failure. Make sure to have the shop run test plans on the engine codes too.

Changing the pan (filter) and fluid on the ZF 8 speed usually takes five or six liters of ZF 8 fluid. Does your transmission have a plastic pan or metal?

[Rand Man]

400626 turbine speed sensor, short circuit to ground or open circuit. This could be a bad connection. I tend to think it is low on transmission fluid. I have felt what it feels like to be low on fluid many times in many different cars, in about 45 years of driving and working on cars. Why is checking the fluid so hard on these? I don’t know what type of pan I have.

To clarify, I have felt the sudden slip and rpm rise in this car. Guess what happened immediately after this symptom occurred: transmission malfunction.

[bmwdirtracer]

I believe that BMW made it difficult to check/fill the fluid because Americans tend to believe that if enough is good, more is better. Hence, no more dipsticks for dipsticks? I wish I could say that I'm joking.

Turbine speed sensor wouldn't be the code I'd expect when you felt a slipping....I'd expect gear ratio codes. It appears you have a ZF 6HP 26 transmission; you'll want ZF Lifeguard 6, not 8, fluid.

BMW sells the service kit as part number:
24152333903
Kit, oil pan fluid filter auto. trans.

ECS Tuning sells this kit. I want to mention that I have never had to use more than six liters:
https://www.ecstuning.com/b-assemble...24152333903kt/

You're going to need some way to pump fluid upwards into the hole, right next to a hot exhaust, and then put the fill plug in while getting burned, engine running. Much fun!

[dworthy]

+1

Just wanted to chime in on the missing dipstick after the 80's on BMW's. So the engineers thought that if you sealed the transmission, it would keep the fluid cleaner and require less maintenance. We all know that fluid will break down over time, and will still get contaminated with clutches, and other wear items of the transmission. So Das Germans thought that this would make it more maintenance free, however it still requires routine maintenance, just a bit less at around 100k vers 60k.

Sorry to say, you have bought the most expensive and least reliable BMW that I know of, I hope it all works out for you!

[Rand Man]

I talked them into changing the battery, due to low voltage codes and they said it was the wrong battery. Transmission malfunction warning still there, but it runs fine.

I will probably start a different post on the thing not starting when I press the button.

[Rand Man]

Starter does not engage when I press the start button. I just paid for a new battery with registration. No start for me, mechanic comes out -vrooom. I guess these buttons go bad?

[bmwdirtracer]

The buttons are a less common failure than the starter itself. What codes do you have in the CAS? Shifter? A weak battery will cause a weak cranking, if it does nothing, suspect a bad starter, or bad signal to start.

[MauiM3Mania]

Merged.

It is best to not create multiple threads which deal with the same car/point in time.

[Rand Man]

It started after work and I drove it home. Runs great, but seems to be stuck in sport mode. If there were truly a transmission problem, seems like they would put it in limp mode. Right now, it doesn’t go into overdrive. 60mph is around 4000rpm. Fun to drive in my curvy backroads drive home, but I need to be able drive out on the freeway now and then.

[bmwdirtracer]

Limp mode is 3rd gear. That's probably equivalent to 4000 rpm at 60.

I can't think of any other way to tell you that this is not a car you can diagnose at home, unless you have ISTA or an equivalent program. Tell us the BMW codes, in words, in every computer.

Seriously, this is the mechanical forum. I don't expect you'll find anyone who's going to tell you that this is a car worth keeping.

https://www.kbb.com/bmw/7-series/200...6324493%7ctrue

Here is the KBB value of your car with 140k miles: $3000.

That said, it probably needs a $6000 transmission.


Clear the codes and take it back to the dealer and trade it for a 6 cylinder BMW.

I apologize for being more forthright than you want to hear. I'm just the guy that fixes them.

[Rand Man]

I had the shop install a genuine battery and register it last week. I also talked them into checking the trans fluid level. It has been running great ever since. No codes, except for one weird-assed incident.

I have a bad leg, and sometimes use a cane. Yesterday, the trans suddenly went into neutral. Several warning bells went off, including “transmission malfunction”. I got it to go into first. Warning said something to the effect of “don’t turn it off, or you may be stranded”. Turns out my cane had been pressing on the “traction control off” button. Turned it off and on again; no problems.

Also, value is in the eye of the beholder. I don’t give a shit what the KBB says, although the NADA says I paid below wholesale for my area. If I end up paying several times what I paid for repairs, I don’t care. This will probably be my last car.

[bmwdirtracer]

I apologize for being negative about your car. It's a job hazard, when you just see broken cars all the time. I wish you the very best and a trouble free car!

[Rand Man]

Thanks. Just to clarify, it is not stuck in a low gear anymore. Freeway speed is no problem.

The other thing I meant to say was, I figured out that odd “won’t start” problem. Turns out, I wasn’t pressing hard enough on the brake.

[dworthy]

As you plan on keeping the car, I would recommend investing in ISTA so you can pull the codes yourself and not have to pay a shop every time. Also "P" codes can be misleading on a BMW, or on any German car for that matter. All you will need is a laptop that can run Win-10 and a cable like this: Amazon.com: AntiBreak ENET Rj45 Cable ethernet Connector Tools to OBD Interface Cable Coding F-Series : Automotive

Over on the Diagnostic Software sub forum, you can read about install, ect.

[Rand Man]

Is it common to get a “oil level at minimum “ warning? I have got a few of these at random. I put a quart in this morning, got another warning about a mile down the road. Seems like if the level actually was low, that warning would display every time you drive it.

Dumb question: is there an old fashioned dip stick in this thing. I didn’t see one.

[bmwdirtracer]

The N62 had the last BMW dipstick, I think. The N63's oil level sensor is on the same bus line as the alternator. If the valve cover gaskets get changed, and two of the bolts get swapped accidentally, that circuit gets fried.

You really need to get the car connected to ISTA.

If you let the car idle for~ten minutes, then rev it, does it smoke? This engine is noted for oil consumption; the dealership throws in an extra quart with each oil change.

[328 Power 04]

The N62 had the last BMW dipstick, I think. The N63's oil level sensor is on the same bus line as the alternator. If the valve cover gaskets get changed, and two of the bolts get swapped accidentally, that circuit gets fried.

You really need to get the car connected to ISTA.

If you let the car idle for~ten minutes, then rev it, does it smoke? This engine is noted for oil consumption; the dealership throws in an extra quart with each oil change.

The N47/N57 diesels had dipsticks up until 2018, although maybe it was there to make the owner feel good that the oil level never goes down. It was an unusual choice.