I have the dreaded Trans Fail Safe Prog on my 2001 X5 4.4 M62 with 5HPZF24.
Its stuck in high gear and the gear indicator light dims out.
This happens while sitting in park before actually moving, if that matters.
Otherwise seems OK once rolling fast enough or in reverse.
Already cleaned and replaced the selector switch, and also tried a known good switch from my 2000 E38.
Have fully charged battery and Alternator was making 13.8v. (though was dead for a while while sitting)
I have also checked both input and output speed sensors and they Ohm the same. I forget the reading but they both matched and neither were completely open or completely shorted.
Originally when starting to diagnose I got the code for the switch (only the very first time I checked) and the Trans Fail code. (reset all of course) Now only the Trans Fail remains. But not with pan off, Lol.
The fluid was very nasty so I drained and removed the pan to change the filter. While the pan was off I started the engine briefly. No Trans Fail and the gear indicator stayed lit. ?????
Now I have completed a full flush and exchanged all of the nasty old ATF for Valvoline Full Synthetic Max Life. After flushing the error is back.
There was nothing horrible in the pan, a few 2-3mm bits of clutch friction material and a normal small amount of metal filings on the magnets. The fluid was probably original. Black and really nasty.
Could this be a wiring harness issue?
With those little bits of clutch should I just get over it and pull the tranny assuming 1st gear clutch pack is toast? I am guessing separate clutches for high low and reverse, is that correct?
Is there a way to semi-permanently disable the Trans Failsafe Prog? So I could test this more completely?