Aw hell. Trans Failsafe Mode hit me..
 

On a 3 hour roadtrip this morning. Cruising along at about 80. Felt a pretty big jolt, and the Failsafe mode hit. Itll go into reverse fine, but stays in limp mode when in D.

I did notice that my cluster dims at an idle, but brightens when rev it a little.

The worst part is, Im 2 hours out. No real tools. Yay.

Any ideas?

BMWs are sensitive to loss of voltage, indicated by dimming cluster. It may not be the transmission. Do you know if your battery and alternator are good?

Any intermittent battery lights on the dash in the past? Could very well be an alternator.

Actually, its had a false Door Open warning for a while.

But over the last week or so, its been throwing a false Check Taillights, and a false Check Brake Lights warning.

After searching the board for a while, Im hoping its a battery or alternator.

Thanks for the replies!

What helped me diagnose this to the alternator was trying to monitor the voltage on the obc. There's instructions on here as to how to get in it.

I'll put my money on the battery or alternator

Most definitely your alt. or battery. These are very finicky when it comes to power. Unlock the cluster and you can monitor the voltage while in motion. Once you do this, before starting you can monitor the batteries at rest voltage. (POS 1)

Vid on how to unlock - BMW E38 E39 Cluster unlock and voltage check Part 1 (E46 and X5) - YouTube

Awesome! Ill let you know tomorrow.

Had to have it towed 150 miles.... lol

Wow crazy. See link in mysig.

So, I haven't had a chance to look the ol' girl over yet. I'm not sweating a battery replacement, but I would love some advice concerning the alternator.


I do have the 4.4, is the alt water cooled? I can replace it myself easy enough, but are the rebuild kits a viable option? I'm handy enough to pull that repair too, unless I need some sort of BMW specific tool... Just thinking out loud (in type).

Or just grab something off of eBay... I hate paying triple for a "Dealer" item, but I did learn a lesson with a window motor recently. Aftermarket regulator? Great. Motor? Complete crap, slow from day 1.

Now I have a laundry list of stuff to fix. I think I'll jam the X into my shop and get everything square.