XSeries-forum

Have had this problem for a while now ,when starting the car and in Park , frequently the trans f/safe warning comes up .
The car battery is 2 years old and is fully charged (Ctec charging when parked). The initial way to make the wng light go out is : switch off ign , remove key, wait for warning to go out and try again. Some times the wng stay out, other times it take numerous times before it stays out.
Is there a wng sensor that is playing up ?
I have just tried slipping the gear shift into neutral before starting  and so far the T W L has not come on.
The warning does not come on when driving the car.

May seem a bit garbled, but have given as much info as possible.

Lez

Difficult Lez, so many things can cause this really need a scan to hopefully point you in the right direction. Are you starting the car with the ctec still connected or are you disconnecting first. As it isn’t happening when driving i would still lean toward battery problem but really need a scan


Sent from my iPhone using Tapatalk

Hi Henry,
No always removing ctek before starting the car.
Any suggestions for best code reader ?

Lez,

You can't usually scan the gearbox ECU for codes with cheap scanners as they only scan do the engine ECU. Best off trying to find someone with BMW software or a decent commercial scanner like a Snap On etc.

I've had this on mine a couple of times too on startup but nothing has shown when I've scanned it.

I have one of Foxwell's expensive scanners (hand held) £300+ and it scans the gearbox, been very impressed and not just because I spent that sort of money but in all honesty over the last 4 years had I went and payed for a scan I would probably have spent way more than that plus you have the convenience of the slightest problem then bung the scanner on.

Even though you say your battery is only 2 yrs old it can still be a low voltage problem cells do sulphate and die, check the voltage when not started should be around 12.2V or there abouts and when running 13.8V to 14.2V.

Well, I thought I would try and explain what I have done to cure!! the problem.
On the advise of Henry3 I bought a good code reader ( Autel Maxidiag Elite MD802) , but it did not throw up any fault codes for the Trans Failsafe).
Sod it , so I have now adopted the following start procedure which works every time.

To start : key in ignition, turn to 1st position, select Neutral with trans selection lever (gear stick) and then start car, works every time, NO Trans failsafe on panel.

I know I may be missing something, but this system works everytime, Road speed is fine( had legal limit +60)
so any ideas out there.
Battery is fine, 2years old.
Have just done 2 x 320m trips in last week, no probs.

Lez

Maybe look at popping it into someone who specialises in gearboxes for their take on it.

Gloucester Road gearboxes in Bristol could do you a full dialysis fluid change at the same time which is always a good move with an auto box.

Or if starting in neutral works for you call it character and ignore.

SB

Feel well guilty now Lez, spending all that money and not getting a fault. Hopefully it will pay for it’s self in the years to come. Not that I’m hoping you’ll get lots of faults. I’ll stop now before I dig the hole any deeper

No Problems Henry, got another tool to play with and as it does all makes of car Suddenly I am very popular with the younger family members,  can't think why!!

Lez

That will be your transmission position switch at fault then.  Around £250 brand new from BMW. I've recently replaced mine with a used one off an L322 4.4i M62 Range Rover (£65) as it was doing the same thing and eventually came up with the corresponding code stored on the transmission ECU.

Thanks for that, at least i now know what the problem is , but why no info on the codes?
Where is the switch positioned and is it difficult to replace?

Lez

Many thanks Henry, at least I have the info now printed off and in the ''to do'' File.

Lez