E39 540i Trans fail safe prog

[Panzh]

Hi everyone, I have finally signed up to this site after browsing it for so long, I have my own problem now and I have came for everyone’s help.

Trans fail safe prog just appeared on my screen while driving one day and it has been a nightmare ever since, it stalled on me in the middle of the road on a red light, the RPM goes up to around 3000 without much power or movement of the car, I managed to get it back home and checked it out, I found out that my car was extremely low on oil and it had been leaking, I believe one of the value cover gasket is bad, I had both replaced about 2 months ago while changing spark plugs and 1 new ignition coil, anyways, I did a transmission fluid change and filter change as well.
well that was two month ago.
Can anyone tell me what the problem may be? I managed to get into the DME and check the connections for coolant and there wasn’t much of anything, I mean there was a bit of dried up coolant in connector #4 but I cleaned it out, I also checked the thermostat and the connection to it and it looked fine to me. I got a video of some new sound the motor is now making also. Any input would be greatly appreciated
https://youtu.be/p_ngp9po9Rc

[1823alex]

I doubt this is your issue, but for my '03 525i I kept getting trans fail safe at random times and it would come and go, I later realized that the reason for it was my alternator. Basically what was happening was the car had like 150k miles on it with an original alternator, but it was like shorting to the casing or something and the voltage on the car would spike up from 12 volts to around 17. Replacing the alternator fixed the trans fail safe for me, although I again doubt this is your issue since it sounds like you are having trouble with it all the time.


Also the reason for the 3k rpm and low power / torque is because that when you get a trans fail safe error the car goes into a "limp mode" type of thing and will usually sit in like 3rd gear (or whatever your 1:1 gear is I think).

[Panzh]

Thank you for the reply 1823alex.
Along with the spark plugs, ATF and filter change I also changed the alternator before I did the coolant flush as it is sitting in coolant as you know, is there a possible way to test the alternator? I remember I got a red battery light on the cluster when my last one went bad. Every time I go back to my car now it’s dead in battery, I don’t know if this is related but I also took a video of some strange electrical issues
https://youtu.be/9AMaGLjzmfY
By the way how were you able to see the voltage on the car?

[phastkat]

A few years ago I kept getting the fail safe mode for reasons I can not explain. Everything on the car was working fine, including the transmission. I checked/changed various sensors, looked for shorts, checked electric currents and draws, and even changed the computer, but to no avail. Eventually I read that the problem could be caused by a bad solenoid on the shifter, so I removed the shifter to take the solenoid off only to find that on the 2003 540i the solenoid can’t be replaced without replacing the entire shifter. So, I changed the shifter, but still no luck. Not convinced the problem wasn’t related to the solenoid, I taped down the shifter locking pin that comes out of the solenoid and I did not have a fail safe message again. I can’t tell you why that worked, but only that it did.

[Panzh]

Thank you for the reply phastkat.

Is there a way you would be able to post up a picture of what that pin might look like? On the 99 540i I have I believe you can take out the two solenoids on their own, not sure if that’s what you meant or just the fact you can’t change them without also changing the shifters, anyways anything helps thanks a ton!

[1823alex]

Thank you for the reply 1823alex.
Along with the spark plugs, ATF and filter change I also changed the alternator before I did the coolant flush as it is sitting in coolant as you know, is there a possible way to test the alternator? I remember I got a red battery light on the cluster when my last one went bad. Every time I go back to my car now it’s dead in battery, I don’t know if this is related but I also took a video of some strange electrical issues
https://youtu.be/9AMaGLjzmfY
By the way how were you able to see the voltage on the car?

Yes, I think you should be able to start the car and you probably could just stick leads on to a multi meter, but if I recall correctly the way I figured it out was when I had my OBD2 adapter plugged in and saw the voltage spiking up occasionally. I think the battery light would sometimes come on as well, but not often.

[Panzh]

Well might have to take my battery to get charged at an autozone or something and give it another go, might pick up a obd2 to check the voltage as well