Trifecta error

**mofaw** · 10-10-2018, 09:37 AM

Hello,

i have 1999 750i.

Had the Trifecta lights pop up. Cruise control is functional, speedometer is OK.

When i run INPA, error shown is :

33 Drehzahlfuehler vorne links Leitungsunterbrechung

Do you think it ABS module or just sensor ?

Thanks.

**georgebest** · 10-10-2018, 10:03 AM

I would guess only sensor, when module fails you get more than one error. Dont buy the cheapest sensor, go with minimum Siemens/VDO.

**mofaw** · 10-10-2018, 11:02 AM

Thank you for your prompt answer.

I did the test again and now I have :

33 Drehzahlfuehler vorne links Leitungsunterbrechung
34 ASC Umschaltventil Vorderachse
86 ASC Umschaltventil Hinterachse

What do you think of this ?

**georgebest** · 10-10-2018, 12:13 PM

The thing is, there is really no way of knowing it what failed. It's always cheaper just to replace the ABS sensors first and see if codes remain. The ABS module is approx $600, that's the last I would replace.
Maybe somebody here has a trick to narrow it down. I took mine to a mechanic when I had this issue and he basically advice the same (replace sensors first and see what happens).
It's an easy job, you can do it yourself.

**asianvenom** · 10-10-2018, 12:29 PM

If you have inpa, jack up the car and have someone spin the wheel wjile looking at the analog signal for wheel sensor.

Why the hell is you inpa in German

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**oldroller** · 10-10-2018, 08:18 PM

33 is left front wheel speed sensor. You can pull the sensor carefully and clean the hole and reluctor ring (brake cleaner and compressed air)
and check the wiring for breaks. reassemble and try it, scanning with INPA while driving.
If erractic, replace. And as the gurus suggest, Seimens OEM only.

**MtekJosh** · 10-16-2018, 03:08 AM

Originally Posted by asianvenom

If you have inpa, jack up the car and have someone spin the wheel wjile looking at the analog signal for wheel sensor.

Why the hell is you inpa in German

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All my error codes display in German too, total pain in my was. Everything else is English thank god.

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**AHolland** · 10-17-2018, 03:35 PM

When I had my problem recently I had to change the ECM? module and I took one from a 540 that worked. I still need to reprogram it for my car instead of the 540 car it came from but most of my problems went away after I changed it out. The drivers side rear ABS sensor is a common problem. I found Delphi parts would not work and I had to go to BMW original before I could clear up that problem. As far as the ABS module goes there is the older style that came on 97 and earlier and then there was a mid year change at 09/98 where earlier cars had one style of ABS pump module and those newer had another.

BBA Reman rebuilds the ABS module for around $200 and they have been doing them for a long time. I sent mine in, thinking it was bad but it was not and then sent it back and charged me something like $65 for the test. I was a little frustrated with them because they said they would contact me when it was done. A week went by and I called and they said it was not done. Called a week later, still not done. Called a week later and still not done. Called a week later and they told me it was finished 5 days after it came but they never called me and when I called, they had told me it was not done so it basically sat for 3 weeks doing nothing. Still in the end the ECM module did the trick although they need to be reprogrammed for the new car. They will work okay without the reprogramming but then a few problems will crop up like it telling me my oil needed changing and to check for my brakes etc which all must have been gone on the car it came from.

**mofaw** · 11-05-2018, 02:53 PM

Hello,

i finally changed my front left sensor (with an eom VDO siemens) and i still have error 33...

But I dont have 34 and 86 error anymore...

What do you think about that ?

Time to send my abs module for rebuild ?

Thanks.