Persistent 5D90 code

veer90

Lieutenant
Nov 16, 2016
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West Nyack, NY
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e90 335i 6MT
5D90 is front left wheel speed sensor electrical defect. Replacing the sensor did not fix it. Disconnecting and reconnecting from car while running and restarting did not fix it. Clear the DSC module codes (through MHD or INPA) and it comes right back.

Any ideas?

Background:

ABS, DSC, and yellow BRAKE light came on 2 days ago when I started the car to drive home from work, and the code was intermittent. Clearing it would actually work for about 5-10 minutes before it came back. Initially, the codes were 5D90 and 5D96 (Drehrichtungserkennung vorne links - front left direction of rotation detection, or something).

Over 2 days it gradually got worse until now, where 5D90 immediately comes back if I clear codes. 5D96 has not come back since I changed the sensor.
 

AzNdevil

Lieutenant
Staff member
Nov 4, 2016
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replace sensor ...clear codes....drive a bit.. if it still shows...clear again...drive... if it still shows... replace wheel bearing
 

veer90

Lieutenant
Nov 16, 2016
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774
0
West Nyack, NY
Ride
e90 335i 6MT
replace sensor ...clear codes....drive a bit.. if it still shows...clear again...drive... if it still shows... replace wheel bearing

I must have cleared the codes a million times at this point lol

Is it possible the ABS/DSC module itself is bad?
 

veer90

Lieutenant
Nov 16, 2016
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West Nyack, NY
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e90 335i 6MT
Is it possible I have a short in the wire? A BMW tech I talked to told me to put a multimeter on the sensor wires to make sure I'm getting a voltage signal.
 

AzNdevil

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Nov 4, 2016
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you can test the sensor to see if its working by checking the voltage difference... you can check for shorts by checking resistance between the two wires

but if you ask me...i highly doubt it...
 

Andy_hastie

New Member
Mar 2, 2019
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Bmw 335i e92
you can test the sensor to see if its working by checking the voltage difference... you can check for shorts by checking resistance between the two wires

but if you ask me...i highly doubt it...
Hi did you get to the bottom of this fault? I’m getting same code along with 5d96 wheel rotation code thinking bearing next was just checking incase it was module or bad wire?
 

AzNdevil

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Nov 4, 2016
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Hi did you get to the bottom of this fault? I’m getting same code along with 5d96 wheel rotation code thinking bearing next was just checking incase it was module or bad wire?

i never had the issue myself..i helped troubleshoot it for someone else though...
 

DarkMatter

Lurker
Aug 21, 2020
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@veer90 Where was the corroded wire? I have a persistent 5D90 code as well. Replacing the wheel speed sensor and wheel hub bearing didn't do anything.
 

langsbr

Captain
Apr 5, 2017
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07 335i 6MT e90
Any update on this? Just started getting this code as well - ordered a new sensor, but worried it might something else.
 

cezar33

New Member
Apr 25, 2023
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0
Hi Guys, i have some problem with my bmw 320 series n47,e 90, 2008, i replaced with oem abs sensors on front left side, wheel bearing, ans still same code, i try to see continuity of the wires and it sound, but i don't know where to look, i checked and all fuses and all working, maybe someone could help me please
 

dzid_

Specialist
Feb 22, 2018
54
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0
US
Ride
135i 2011 DCT
I had rear right sensor failing and then failed permanently. It was eroded a bit by rust flakes. I changed it and the error happened only one more time after clearing, and then went away.
HOWEVER, few days later front left sensor started to be reported. So I thought that's suspicious but I changed the sensor anyway. This one didn't have any rust on the shaft ring.
Replacing it didn't help. Actually now the error shows up right after the ignition on.

I must say that I had other corrosion issues ever since two years ago I shipped the car in the closed container over the ocean. Do not recommend... Some nuts are visibly rusted in the engine bay. Inside the cabin, downshift paddle stopped working for a while. And to this day volume button sometime dials last number instead of changing volume.

Anyway, there are two types of sensors and on my 2011 135i I believe there is newer version (which is more difficult to test). The old one would change current depending on proximity and new one is 1-wire digital signal.
I am yet to find find right method to confirm that any of the sensors work... Maybe they have to be tested when installed.

Another symptom is that during tight turn and braking ABS thinks I am skidding and the pump starts doing abs intervention.
Did any of you had that? I have M3 steering rack so it maybe this is due to yaw/steering ratio mismatch..

So I don't know. Maybe one of the DCS power stage is failing and not providing enough current to the sensors (since the error moved from one wheel to another).
Or both sensors were failing in the same time. One due shaft rust and second maybe due to wiring rust or just itself.

Freaking mystery.


EDIT:
1. I believe the two cheap new Chinese sensors I bought are dead as well. So I bump up the theory that it was just two sensors just failed more or less at the same time.

2. The protocol might be the same as in F82, as suggested by E90 Bentley manual:
1682898152859.png

Pdf:
1682898062864.png

I need to look more into this. I think rear sensors are simpler and use a reluctance ring, while front ones are more precise and measure magnetic field.

3. I connected the front (OEM - maybe faulty) sensor through 147ohm resistor to a power supply and measured the voltage drop using scope. There is a waveform generated every 165ms
1682900704412.png
and looks like this (7-14mA):
1682901286881.png

Wave doesn't change even when waving a magnet in front of the sensor.

4. Rear, OEM presumably faulty sensor doesn't produce the square wave. Just constant 7mA draw and waving a metal in front of it does fix it.
5. One of the chinese sensors that I have is producing the same square wave, except every 150ms and it can have a big spike when bringing magnet very close:
1682902759688.png


6. So I believe there are two types of front sensors (even though they look the same). 34526870075is active with the protocol example shown on the scope above and 34526762465 is PWM responding directly to the reluctance ring. The latter is present on crappier-engine cars - according to realoem (presumably without hill hold feature). The 34526870075 works with magnetic bearing plate and the other with reluctance ring. Rear axle has reluctance ring and probably just one version of the sensor.
 
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dzid_

Specialist
Feb 22, 2018
54
35
0
US
Ride
135i 2011 DCT
I fixed my issue finally. As I said, there are two different types of front sensors and they both fit mechanically. The Chinese version of the sensor for only $8 was the correct one for my 135i. Will see how long it lasts. In the end.
It was very easy to replace. The wheel doesn't even need to be removed. Just full turned in one direction to unscrew the bolt and then the other to deal with the connector.
Now the wheel speeds look good on the CAN:
1683039394624.png

It is still a bit of mystery to me that the front sensor failed a week after replacing the rear one.
 
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AzNdevil

Lieutenant
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Nov 4, 2016
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i have never bought the expensive sensors myself since the cheap ones last for a few years and are very easy to swap out....

last time i did my sensors i found the harness plug itself to have cracked but the sensor itself was fine.....managed to find a similar new plug luckily on aliexpress, cut one of the plug index keys out and fixed it

anyways glad you got to the bottom of the issue though