I am trying to source an old PC with Window 10 so I can run INPA software pack. Then I can do some great information.
That S.A. sensor was replaced about 4 years ago, can't imagine it went already.
AT this point I just want to keep it going for as little $$ as possible, as it is so old n 250K miles is great with all original engine/drivetrain except front axles. I know I can physically test those s.senors besides code out.

You need to read codes to know vs guess. Any part can fail any time there is no "should still work", but I've seen plenty of times things can get confused especially if there is a voltage drop.

I've had an sas error that happened twice I think and I just recalibrated and right as rain.

Absolutely, codes are invaluable ,but I find if there is a physical test to add, it can be helpful for a more precise diagnose. The trifecta is a royal Pain. But at least here in FL I don't have to stress over it not working. Just practice safe, stable driving attitude like they taught us in BMW driver training.

One nice feature of driving these steptronic systems is you can lock into a lower gear and keep the engine rotation closer to traction needs. I used to do it all the time when first learning to drive manual in the brutal cold, snowy winters in Maine. And some years later had a wild experience driving my E30 manual around in 2nd n 3rd gear through the power band in the upper revs. I miss that thrill. But youre right, gotta eventually, when it cools off here, get that darn Trifecta issue resolved, but probably not swap into a 2WD, don't have the time or the money.

2WD convert possible?
 

Wife's car just started having a trifecta. When I pulled the codes it flagged the right rear sensor.

I just replaced the right rear bearing.

Cannot be a coincidence. I figured either the old sensor just doesn't want to listen to the new tone ring or I damaged the sensor by leaving it in when I knocked off the hub with the slide hammer.

Replaced with a knock off sensor because it was $20 v. $90 and I wanted to see if it was actually the abs module and the $70 savings is 1/3 of the module repair if needed.

So far no trifecta. The sensor takes all of 20 minutes to replace so I wasn't too concerned about using a branded part. I'll post my lack of wisdom on that should that part fail quickly.

I had a knock off fuel pump fail after 10 months but they replaced under warranty and the replacement is working fine. I also bought an OEM pump as a backup since I have a pair of X5 and eventually one of the pumps will fail and I want a quality pump that takes most of a week to deliver. Now I just need to have somebody bring me the pump from my house. (I'm rarely ever more than 90 minutes from home)

wow, that could be an issue for me,both rear bearing are original. Front were new about 70K miles ago when axles were replaced. Does the fuel pump fail while driving or only when you go to start up? I should find a solid brand replacement I think, mine is original: 01/250k miles. But first I should diagnose why my overflow bottle was practically empty yesterday. Seems fine now, no leaking.

Fuel pump can fail at any time. You can have some warning as the pump can be weak before failure and not provide enough extra pressure to run the siphon jet.

The normal lifespan is 5000 hours with E10 gas maybe it's 5-6000 I forget, but that usually means 130-180.000 miles.

I would not necessarily replace but buy and have on hand pierburg or Bosch pump (just the pump not the whole unit) for when it fails.

Usually the pump ultimately fails at start (attempt). It will eventually wear the brushes to nubs and at one point it will land at a bad spot on the commutator and won't turn.

You can likely get it to start with a firm tap on the top of the tank (to get home without a tow).

Bearings can last forever. I wouldn't preemptively replace them.

Recently I've discovered the main cause of bearing failure is impact. Not time or miles. Pot holes basically.

Hit a pothole especially where it torques the wheel sideways and you could damage your wheel bearing in the first mile of driving.

I replaced all four wheel bearings on wife's X5 now (all failed between 130-170.000), but mine has three original and the right front has been replaced twice. (at maybe 150 and 176,000 mi). The left front needs replacing but I couldn't tell until the noisy right was first replaced.

Currently around these parts e53 3.0 X5 models are hitting the self serve junk yards. The prices on the related components are very reasonable. I would suggest getting yourself an extra set of what you need at less than $500 and that should last you a really long time as designed.

That fits with my experience as well. :thumbup:

But moreso than potholes, I think the use of hammers when working on suspension components damages bearings. Standard practice industrywide though ... creates more work down the line. Do it all the time, nothing to worry about, the hammers make it so easy and fast, 'nuff said ... Easy to think that way if you only work on other peoples cars where you don't see failures down the line, or if you don't keep you own cars long enough to see the longer term consequences of the impact damage.

I always think of bearing surfaces as being made of glass - i.e., hard, strong, but brittle, when working around them. I'll use pry bars, pullers, and light hammer taps on the right spots - making sure the force is not transmitted through the bearing surfaces.

And I've never ever had a wheel bearing fail on any of my cars (now with an average mileage of around 150k miles in my fleet). And only once about 20 years ago had CV joints fail. Keep bearings greased, clean, and avoid impact and they will outlive most things on any car.

EDIT - but I'm not talking about things like alternator bearings that get hot, lose their grease, do wear out, and are worth replacing based on mileage if the alternator is already apart. Similar with pulleys - once they lose their grease ...