trans failsafe prog

[dicky84]

Hi I am new to this site and only been a bmw owner for 2 months.trans failsWhat II am having is when I turn my ignition on I get the trans failssafe prog come up i needed to change the batery so i have done that alternator is charging fine and the car is working fine no problem up and down through the gears manual side is working fine no problems engine speed has not changed and i get no other warning while driving so a can not see anything wrong with my x5 only this message .
Is there anything I should be worried about and can I clear  the trans failssafe prog myself with only a standard code reader.
Thankyou

[Steamyrotter]

Hi And welcome

Do a search on here (which you probably have) on the many various forms of the Failsafe message..

We will need a little more info like Model, year, engine & box (5/6/8 gear)

As it comes up straight away then there is a hard fault there.
The only way you will know for sure is to read the codes and then go from there...

Search for the various scanners on here also and you will see whats around.

Or let us know where you are and there may be someone close by who can scan it for you...

[dicky84]

Hi well my x5 is a 2003 30i sports 30i 5 speed box and I live in Hadleigh Suffolk not far from ipswich colchester or sudbury I will try to see what codes there might be but I only have a basic reader for ecu and I think I might need to get a better one

[Steamyrotter]

Ah ha
That will be the GM 5l40E box.
(I have had a little experience with them!!)

Being a hard fault it may be somethink like a speed sensor failure, or a solenoid coil gone.
There are ways to check these, but code reading first is the best bet.
As you have all gears in manual then i wouldn't expect the gear change solenoids to be the problem (There are only 3 of them) but there is a Pressure regulator valve, and a lock up clutch valve.
There are 2 speed sensors, one on the input ring, and one on the output ring.
All these are accessible with the box in the car, but you have to drain it and take the sump off - not too hard but a fright if you are not used to it!!  They are controlled by a cable plugged into the rear Right of the gearbox.

You may need to see the pressure the box is generating also..
Normal in park on tick over is about 50-65psi.
Failsafe mode will set the box to max pressure (up to 230psi) as will a failed pressure regulator solenoid coil..

So get codes read (you will need something a little more in depth than a standard plug in jobby, but search the net and here for what works)  Check pressures and, if you find the link i put on previously for the rebuild manual, you could check the coils and sensors for correct(ish) readings from outside the box via the plug at the rear..

[Smeeagain]

Before you get in too deep ....... I changed a dodgy battery and still had the message. I did the standard clearing procedure (without a scanner) and it went away and never came back.

Have you actually don't the standard reset procedure? Daft question perhaps but don't want you rushing in if you dont need

[X5Sport]

[quote="Steamyrotter"]
Ah ha. That will be the GM 5l40E box.
(I have had a little experience with them!!)
[/quote]

Only a little.... >:D

[dicky84]

I have just put my basic code reader on and it came up with code p0102 have looked it up and it comes back as maf or var a circuit low input so could it be the alterbator as there is a new battery on the car and the trans failssafe prog only comes up when I first start the engine then  goes out after 3  seconds

[dicky84]

On another note when I cleared the fault I got the trans failssafe prog come up while engine was running turned it off waited a little while then started her up again got the trans failssafe prog come up as before cleared the fault with the maf then came up again with the trans failssafe prog  so could it be linked

[Steamyrotter]

Re-Reading the original post..

Transfailsafe usually locks the box initially in 5th, and then 4th on a restart and cuts off the pressure solenoid circuit to give full pressure.

Does it drive OK in "D" and "S"??
The way i read it was you tried in manual and it was OK..

It could be something silly like being set in transport mode or an actuator test that has not been cancelled correctly...

To check that you will need something like INPA or access to other test gear like AutoLogic or (if you are desparate) go to a dealer...

Does the lock up clutch work as expected??
To test drive normally to approx 40MPH and check revs, apply slight accelleration - Revs should rise due to torque convertor "slipping"
Get to 55-60MPH then do test again.
Revs should not climb as quick, but fuel consumption meter will drop, as the engine is locked to the box.

If you get Torque convertor slip at that point then it may be the solenoid, valve or Torque convertor linings failed..
(The latter though would not bring up Transfailsafe immediately though)

I think battery & alternator issues are not that relevant here due to it coming up so quick...

[dicky84]

I have ordered a new maf  when it comes I will fit it straight away clear the p0102 fault and then see if the trans failssafe prog comes up I will let everyone know what happens ( keep my fingers crossed)

[dicky84]

Well my new maf arrived so I fitted the new maf canceled the fault code started  her up and  bingo no trans failssafe prog came up so everything is running great actually better than before so it was this little damn sensor causing all my problems hope this can be helpful to someone else with the same fault I had