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Discussion Starter #1
Hello Everyone!

A friend of mine recently bought a 2007 M5 SMG with around 65k miles on the clock.

Everything on the car works fine except for the SMG. However, the shifts are smooth. Below are the things that we have noted.

1) The car skips 6th gear most of the times. If you shift up from 5th it will go into 7th and if you shift down from 7th it will go into 5th. It very rarely goes into 6th. Whats even more strange is that there is rarely a fault message. And if we scan the car even after a fault message, the fault codes are not stored. The autologic shows to fault codes at all.

2) The car always starts in manual mode. In fact, it does not go into auto mode. If we push the shift lever to the right to put it into auto mode, it resets the shift speed to 1 but stays in manual mode. We even tried programming the M button, but it does not go into auto mode at all.

We have done the following hoping to fix the problem without success.

1) Flashed the DME and SMG ECU with stock software and performed adaptations.

2) Replaced the SMG and transmission fluids and relay.

We suspect that the previous owner has played around with the software on the car but we dont know where to look next.

Appreciate all suggestions and advice.

Thanks
Hasan
 

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My car did this to me a few times in June so I just replaced my clutch at 100k miles, and the SMG pump motor. I also replaced the clutch for pin and got the Bimmerzone updraded guide bushing.


Post clutch replacement it has done this to me again; twice. Most recently this weekend, both times after good stints of spirited/aggressive driving.


This weekend when I tried to downshift into 6th and 2nd, it couldn't find the gear and wouldn't shift into it and then I got the red cog (I was doing a bear mountain run with a few M cars).


I pulled over, turned the car completely off and then back on and it cleared the red cog, but wouldn't shift into 2nd or 6th. When we came to the rest stop and I let my car sit for about an hour, it shifted fine into all gears.


This has me wondering if this is a overheating issue and I want to look into whether or not my transmission cooler is effective or I need better fluid.


Also, the new OEM clutch doesn't seem to grab like I thought it would (yes I followed the 500mile break-in).
 

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no codes?

i would try flashing the SMG to the latest software.. Also how about the engine software stock?
 

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No codes at all. Done the DME and SMG ECU flash as well as SMG and transmission oil change.
Ok.. The flashes are the latest oem software correct?

Next step i would try is full 3 step adaption..

I fear if that doesnt help and the car is indeed on the lastest oem software, there is a hardware issue and the trans will need to be dropped, taken apart and checked.. Starting with the shifting solenoids on the top of the trans..
 

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Discussion Starter #6
Ok.. The flashes are the latest oem software correct?

Next step i would try is full 3 step adaption..

I fear if that doesnt help and the car is indeed on the lastest oem software, there is a hardware issue and the trans will need to be dropped, taken apart and checked.. Starting with the shifting solenoids on the top of the trans..


That is correct. ECUs flashed to latest OEM software. Full SMG adaptation is done.

Is it possible to replace the shifting solenoids?
 

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That is correct. ECUs flashed to latest OEM software. Full SMG adaptation is done.

Is it possible to replace the shifting solenoids?
The shifting pistons cannot be repalced or the housing, it must all be replaced unfortunately, i have seen one example of a broke shifting piston housing on the board.. But that isnt the case here..

Gear 6 is tied with 7 within the hydraulic shift housing.. So usually anything wrong with 6 would show with 7.. The same shifting piston, same housing, same shift solenoid.
Im gonna guess its a actual trans issue within.. But im just using my best knowledge which might not be the answer for this specific issue

Any work done otherwise on he trans prior to this issue arising?
 

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I notice that this only happens to me with extended driving, so I'm assuming it's a heat issue. Are the synchros sensitive to heat? I'm also wondering if there is a better transmission fluid I should be running that will operate at cooler temps if that's the case.

I did some searching and there doesn't seem to be any aftermarket transmission cooling solution.

But I definitely notice the issue after I've been driving for over an hour or so and weirdly enough only in M mode at high RPM shifts.

Not sure I want to go down the route of buying a used tranny and there don't seem to be any rebuild options..................................
 

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Suck the fluid out of hydraulic tank and refill with fresh new fluid.. drive the car for a few mins and repeat.. try to flush some dirty fluid out of the system... see if that helps.. of course remember to bleed the block and slave cylinder when done via dis or ista.. cheap and easy try..

Next step, if the above doesnt help, would be to drop the trans and swap the shifting solenoids on the shifting block on top around and see if the issues follows that specific 6-7 solenoid to say in place of the 3-5.... If it does follow, then you know the solenoid is bad and its a, simple solenoid change and that its not the actual trans itself..


Of course after this swap, it will need a trans adaption via dis or ista..

Solenoids swap, This would be done after verifying that latest oem softwares have been flashed, smg hydraulic system has had both bleeding procedures done, trans oil fluid level is correct..

Only things i can think of to troubleshoot this before getting a new full smg hydraulic system..
 
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