E39 ABS/DSC issue

[Doctor Gollum]

Using the very helpful guide here... http://www.bimmerforums.com/forum/showthread.php?1395944-HELP!-ASC-ABS-Problem-E39-523i

Suspicion fell towards the osf sensor as the gearbox is playing silly buggers in automode and not changing up to 4th or 5th... manually is fine. Speedo and cruise control also working as normal

I have dug out the multieter. For some reason, my meter registers the resistance on all four sensors as an overload, both forwards and backwards

But, the diode readings are all between 1.941 and 1.974v and all OL in reverse. Also all four sensors also produce a voltage when the wheels are spun, increases with wheel speed.

From this, would it be reasonable to assume that the issue is most likely with the ECU itself?

Will pull the osf wheel in order to double check sensor is clean, just to rule it out...

[Doctor Gollum]

Right, wheel off... Sensor removed and cleaned, but looked ok



Wiring checked between sensor plug and ecu plug and intact, diode voltage at sensor matched reading taken at ecu plug.

All back together and lights went out once the car moved. Gearbox back to normal too...

Osf wheel bearing needs doing sooner rather than later so it might be that with the slight play that the sensor 'lost sight' of the hub

[Marks DTM Calib]

Most sensor related failures I have seen have been wheel bearing or the reluctor rings failing/cracked.

Usually gives an incorrect signal code or similar, when viewing live data you get a lower speed on that corner.

[Doctor Gollum]

Reluctant rings on these are built into the bearing seal
... Will replace bearing before sending the ecu off

[Doctor Gollum]

Lights are all back on again...  speedo, cruise and gearbox all working as normal...

[henryd]

Have you read codes front ecu ?

[Marks DTM Calib]

Lights are all back on again...  speedo, cruise and gearbox all working as normal...

Speed signal for rear wheel drive vehicles is usually derived from the rear wheels 

[Doctor Gollum]

Have you read codes front ecu ?

That will be my next port of call, but don't have the facility.

Cruise and box now not working... Cruise and speedo come from either side rear, as per bimmerfest guide, nsf is steering yaw reference and osf is box...

Fault could lie with the steering column sensor as I get the airbag light on cold damp mornings, clears once car is warm.

[aaronjb]

Is the E39 an OBD shaped port or the older round diag port under the bonnet?

[Doctor Gollum]

OBD port next to drivers cubby

[henryd]

Is the E39 an OBD shaped port or the older round diag port under the bonnet?

I've seen a few with both

[Doctor Gollum]

Is the E39 an OBD shaped port or the older round diag port under the bonnet?

I've seen a few with both

Haven't noticed one in the engine bay but definitely one in the drivers cubby

[pauls]

If mine works you can always use it

[JamesV6CDX]

Al, I have the diagnostic lead and BMW INPA software that will do codes, live data, and actuator tests etc on all systems.

If you wish to borrow it just say the word

[Doctor Gollum]

Codes read, cleared and returned as soon as car moved...

Right Rear Wheel Sensor Speed Signal Implausible. Or words to that effect...

Have removed, cleaned and refitted sensor to no avail.

Would it be reasonable to assume that this sensor is toast?