Trans failsafe + no gear indicator on dash
 

Hello everyone

New issue on the X

So to resume the car would get into trans failsafe and also no gear indicator on dash, it drive but in limp mode. Sometimes getting the key off for 30seconds and key on again fixes it.

It works or doesn't work after turning the key then stay working or not working until next key off/on. It doesn't happen while driving when the issue isn't present.

But since today it refuse to work again no matter what, I didn't try clearing the codes again.

Codes are:
P0753 shift solenoid 'A' electrical
On dis: solenoid valve 1

So is it simply the solenoid or it could be something else or low oil in the transmission?

Looks to be a bad solenoid based on the error. I had this same issue on my e38 until one day, no idea how but it came back to life on its own. I did end up replacing the trans with a lower mileage rebuilt one since the original one had high mileage. Do you have a 4.4 with a 5hp24?

Yes it's the 5hp24. Car has 300k km

I don't trust generic P-codes to always be accurate, but....

As someone who has had this issue before I will give you all the places to look.

1. Interlock cable @mechatronic gearshift.

2. Magnetic reed switch on the valve body mechatronics. (if lucky cleaning will fix)

3. Solenoid and valve body seals.

4. Shit luck and it's a crack in the valve body channels allowing pressure bleed over.

A scanner like the Foxwell nt-510 or nt-520 (200 USD) will show you more data and what your gearshift is in vs what the transmission is in. A difference between the two will give you the symptoms you described, some of the fixes are easy, some cheap and some completely peg your fun meter...

Here's some pics of the different repairs I had to do, but missing the gearshift and reed switch pics.

Also be very very gentle with the gearshift cover as the tabs break easily and over tightening the shifter will put some gears out of position enough to not engage. https://uploads.tapatalk-cdn.com/202...3fd0bcf7cc.jpghttps://uploads.tapatalk-cdn.com/202...99745dca1b.jpghttps://uploads.tapatalk-cdn.com/202...474317b085.jpg

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Thanks for the infos

Today my girlfriend used the car and told me when in reverse it accelerated by itself and she almost hit a wall.

What do you think it could be with that added info ?

Honest guess....

Transmission wasn't engaging and she gave it more throttle and then it engaged under high RPM.

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Valve body then ? Or clutch or torque converter?

Truly hard to say but do you have your fill times and clutch pressures? Any codes (not p-codes) BMW ones?

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I'll check on inpa.
Error in dis is solenoid valve 1