01 740iL - Trans failsafe, service engine, abs

New to this site but hoping yall can help. Currently own a 2001 740il just reached 100,000 miles. Has been a great car until recently one day at the bank I put the car in reverse on an incline then put the car in drive all was fine will I pulled out. Gauge cluster died, trans failsafe message appeared car fell into limp mode and started running sluggish, abs light was present and brake light appeared briefly. Made it to the house and parked it, next day went out and started it trans failsafe message was gone and cluster was working however the service engine light was on. Had the codes pulled changed both cam position sensors along with having the battery and alternator checked, both of which are good. Now the car alternates between showing trans failsafe and abs along with cluster dying and cluster working with service engine soon... Im so lost at what to do next and any help would be great

I realize you mentioned you had your battery & alternator checked, but this sure sounds like a battery problem to me. If you had your battery & alternator checked by someplace like AutoZone, I'd try test #9 on your instrument cluster, or, use a multi-meter on your battery, just to double check.

Like sealbeach740 stated, double check the battery/charge. The liquid-cooled alternator should provide 13.2-14.5 V of charge. Also the amperage of the battery should be checked. The reason for your "disco lights" on the dashboard might be insufficient power supply to modules like transmission, ABS/brake, or even the DME. I would suspect a wiring harness issue also , a fault ground cable for instance.

What is test #9 and how would I go about doing this?

Originally Posted by itrcvc96

What is test #9 and how would I go about doing this?

The on board computer of the BMW's have the capability to do couple tests using the instrument cluster. In order to do that, you need to unlock the instrument cluster first. Few of these test are Mass Air Flow sensor test, engines temperature, fuel gauge or #9 test charging test. There are a couple threads on the E39 section about how to unlock the instrument cluster and do the tests, or you might find them on youtube (few).

@ itrcvc96
i have a 2000 740il and am having the same issues. Did you ever get this resolved?

@kris b it actually ended up being my abs module. I took it to a friends shop and he initially thought it was my cluster, which is apparently a common problem in this model, but we ruled that out. We unplugged the abs module and the problems did not get any worse nor better and he happened to have another module in the garage so we plugged it up and all the problems were resolved.

Originally Posted by itrcvc96

we plugged it up and all the problems were resolved.

Interesting. On the E39, if we did that, we'd have problems from not recoding the foreign ABS control module. I guess on the E38, you don't have to recode the VIN into the new (to the vehicle) module?

The problem is usually a single wheel sensor goes bad (wires or the <$100 sensor), or the ABS control module goes bad (a steel resistance-welded wire lifts off its bond pad, Bill kindly ran a full autopsy here). Debugging is best done with a DMM; an OBDII scanner can ONLY find "communication errors", i.e., it cannot tell a bad speed or pressure sensor from a bad ABS control module and will often report the wrong problem because it isn't inserted BETWEEN the ABS control module and the various sensors (see extensive reports by 540iman on this). The ABS control module costs ~$150 to $300 to rebuild, ~$500 to replace; if you put anything back on other than your original ABS control module, the VIN will need to be recoded (15 minutes with a GT-1 or Autologic or similar; impossible otherwise). You'll need to clear your OBDII DTC codes after you fix everything if you plan on passing smog tests that week (ask me how I know). If you need to replace a speed sensor, don't go aftermarket; get as close to OE as possible.

I made it sound easier than it really was. It was not simply plug and play but as to what exactly was all entailed in installing the new abs module I'm not sure. I know he said certain serial numbers had to match because there where diffenent models of the module and that the new module had to be reprogrammed

Originally Posted by itrcvc96

I made it sound easier than it really was. It was not simply plug and play but as to what exactly was all entailed in installing the new abs module I'm not sure. I know he said certain serial numbers had to match because there where diffenent models of the module and that the new module had to be reprogrammed

He probably recoded the VIN:
- What happens if you don't code the VIN into a new ABS module

I was going to say abs as well

Sent from my DROID4 using Bimmer App

@itrcvc96, thanks so much! I will test and rule out batt first. This has been going on for a couple weeks now and at least once I have experienced loss of power steering, felt like nothing between me and the tie rods! This loss could be completely that of ABS malfunction correct? Since ABS allows control of steering in heavy braking...? Although I don't recall that I was braking when I felt the tight steering (during a wide u-turn).