I think I have a failed wheel sensor and mo...

So on a quick run down to San Francisco, my DSC, ABS and Brake lights light up. As a bonus, on the way back to Sacramento, my SES light lights up. 1999 540it, M62TU



I hook up Carsoft and it reads three codes, one on the ABS/ASC module:

31 - Drehzahlgeber Kabel hinten rechts fehlerhaft, which I believe translates to
"Tachogenerator cable in the back right incorrectly" or rear right wheel sensor is bad.



I found a procedure in a DIY section to test the sensor which I'll try tomorrow. Gotta figure out my multimeter on how to correctly use it to test the sensor properly.

I received these two errors in my Instrument Cluster Module:

BC - Bremsflüssigkeitsstand Verteilung - Brake fluid conditions distribution

90 - Spannungsversorgung Klemme 15 fehlerhaft - Voltage supply clamp 15 incorrectly


I'm searching out what these two could relate to. Just mentioning here in case some else got these codes recently. No other clues that might be triggering the SES light. Something to do tomorrow...

P.S. Someone asked about translating the Carsoft German to English. Sorry, I haven't used Carsoft in awhile, but anyway, I typed the German code phrase into Yahoo translator to get the English translation.

Originally Posted by BlackBMWs

How come the idle is so low?

Maybe you can try cleaning the sensor with crc electronic cleaner. . .

MAF? hmmm... Cleaned it about a week ago with CRC MAF cleaner.... Good eye, didn't realize it was idling that low. I'll look up what it's supposed to be at, I would think around 700 rpm. I'll cross check it with the live Carsoft feed to see what it reads at the same time.

I meant you could try to clean the wheel speed sensor

Ah, big difference! my bad, thanks I'll try that.

500 RPM warm idle without load, 700 under load or cold

Originally Posted by bmw_n00b13

500 RPM warm idle without load, 700 under load or cold

+1 Your idle is right where it should be. I forget, but someone will jump in- doesn't the right rear sensor also send signal to the speedo? It would be great to see a list of what each sensor does beside drive the ABS/DSC system.

Well, it was warm as you can see in the photo, so I guess it's O.K. I thought when I was looking at Carsoft Live data last night, it was around 530 rpm or so...

Originally Posted by TheStig

How come the idle is so low?

Maybe you can try cleaning the sensor with crc electronic cleaner. . .

My 99 540it idles at the same rpm(120k miles)

Hi again,

As you know, I have the same problem (ABS malfunction showing up on the DASH) ... so let's keep in touch in these threads so we can troubleshoot together.

I've been all depressed about other things (relationships, job, life, etc.) but I'll try to get some Carsoft datapoints this weekend.

It would be nice to have clear pictures of all the parts so I will try to find them all this weekend and snap photos. Apparently I've seen the sensors when I did my brake job (I don't remember them though) so I'll look there and in the engine compartment.

PS: How is my idle?

Your idle is higher than mine is, when warm..

Originally Posted by 540iman

+1 Your idle is right where it should be. I forget, but someone will jump in- doesn't the right rear sensor also send signal to the speedo? It would be great to see a list of what each sensor does beside drive the ABS/DSC system.

Rear drivers is used for the speedometer, and thus odometer, any OBC calculations relating to speed. It also effects your gas gauge. The rear passengers wheel is designated for cruise control on DSC cars.

your ABS module is bad. The right rear wheel speed sensor is just a decoy. when the abs module goes bad it always throws codes pointing to the right wheel speed sensor. I had this problem last november and needlessly had the right wheel speed sensor replaced. send the abs modul to Module Masters and for $300+ they will rebuild and guarantee. I did and it fixed my problem. this is a chroni problm with all e39s. the abs module is too close to the engine and it gets very hot which causes the solder to crack on the board which then causes all these problems.

I had a similar issue with my 528i, except I lost the speedometer as well. To check the wheel speed sensor I read somewhere to swap the left with the right and see what happens. The test assumes that both of them did not go bad.

I tried this but in my case it made no difference. I ended up doing the Module Master solution and it solved the problem. Hopefully you only have a bad sensor, but take heart that a MM solution is the fraction of what a new one costs.

Best of luck!

Originally Posted by jkgrage

your ABS module is bad. The right rear wheel speed sensor is just a decoy. when the abs module goes bad it always throws codes pointing to the right wheel speed sensor. I had this problem last november and needlessly had the right wheel speed sensor replaced. send the abs modul to Module Masters and for $300+ they will rebuild and guarantee. I did and it fixed my problem. this is a chroni problm with all e39s. the abs module is too close to the engine and it gets very hot which causes the solder to crack on the board which then causes all these problems.

It will eventually go bad, but dont jump on the modual. A simple ohm test will tell you if the sensors are bad. I, for example, have a good modual with a bad rear drivers sensor.

Just in case anyone has not noticed, Module Masters has had to step up and sell on Ebay as there is very excellent competition out there right now. Module Masters re-builds can be had for less than the $300 on their web site. Also BBA is under $200 and the one I used with excellent results (as did another poster here) is ATE1234 which I got for $100 and carries a lifetime guarantee. I think ATE stands for Automotive-Truck Electronics. They rebuild MB/Saab/Audi/BMW/ and most American cars so they are no fly-by-night outfit. Since I know of no forum sponsors selling this service, I see no reason not to post my complete happiness with ATE. they were $99 and $105 using ****it-now. Get it while they are slow. Don @ ATE answered every single email and they answer their phone as well, and that is 1/2 the battle. Turned my module in 1.5 days. They pay return postage too!