Speed Sensor not reading
 

So, ive read through the mountain of info on this subject (trifecta) and I have some codes that I need to work through. Basically trying to see if my issue is NOT a failed abs module.
Among my many codes is one telling me that there is no signal from the rear left speed sensor. As far as I know, this sensor is responsible for the speedo?
The speedo does dip in and out every few weeks without any warning, but for the most part stays on. The sensor in question is brand new and I have checked for continuity from the harness plug to the pins at the abs module. I gave the wires a good jiggle, jiggle, shake, twist to see if there was a break but nothing. SO, the wiring is good but the module still says it cant see a signal. Amongst the other codes is a "pressure,line" code which i believe is a brake pressure sensor and "intermittent signal" from the front right which I haven't checked yet.
Am I chasing worthless issues and just have a failed module? Or is there something else at play here. Any ideas on tests or checks I can do would be greatly appreciated.

As a general rule, once you have established that the sensor and wiring are OK, it's highly likely to be the module.

If the pressure line code requires that you replace the module anyway you might as well do that first before spending more time on the speed sensor circuits.

Is the pressure line code not related to the brake pressure sensor which is a seperate piece of the module?

I have no idea, I have never dealt with that. Maybe someone else can chime in ??

So, a little update. This weekend we had to take this vehicle for a road trip as the other vehicle was out of commission. While we were driving, we had to make a rest stop so we parked for ten minutes. When I started the car and we took off, I noticed that the speedo, odometer and mileage gauge were not working. This happened multiple times throughout the weekend. I noticed that it would only turn on/off when the vehicle was shut off and turned on, not while it was driving.
Is this further evidence that the module itself is dying? The trifecta lights were on regardless of the speedo working or not.

Maybe have a look at a wiring diagram, if I remember correctly someone else had a similar kind of problem and it was found out that the speedo signal actually comes through the ABS module and not directly from the wheel sensor. That still doesn't really prove that your wheel sensor signals are good though.

Yes, the speedo reads from the drivers rear sensor through the module.
So, the loss of speedo, odometer and fuel mileage gauge leads me to believe that its a total loss of signal from the module. Still baffles me that the module says there is no signal from that sensor. Consistently the same three codes keep coming up, even after clearing them every day. But im not getting a code saying the module is defective.

The module internal failure is lost contact between module connector an circuit board. So regarding diagnostics it will show the same as lost signal from the sensor. If the sensor is a known working one and the wiring between sensor and module is checked, it has to be the module internal wiring.

I have confirmed that the wiring between the drivers rear sensor is not broken. I've also reversed the rear speed sensors and the same readings come up.

Then I think you are looking at getting a module.

I agree with you. Not what I wanted to do in terms of cost but this is the path I chose when I bought this vehicle!

If you raise the vehicle, remove the rear wheel speed sensor put the vehicle in neutral and slowly rotate the back wheel with some fine sandpaper on a popsicle stick rubbing gently against the pick up surface, you may clean off the surface and solve the problem. We do a lot of fabrication and grinding in our driveway and when I had the same problem, I had picked up some metal filings on the speed sensor and pick up surface. Welcome to the rust belt. You can also get corrosion in there and get an interrupted signal. I chased this for an annoying length of time until I cleaned it.

The reluctor ring is in the bearing rear seal. So I wouldn't touch it with anything abrasive.

https://c1552172.ssl.cf0.rackcdn.com/1504073_x800.webp

Only enough to clean it off. I agree with you. I looked down there with a bore scope first and it was pretty crud filled. Short of replacing the part, this was my best option.

Brake cleaner (and compressed air) should be enough. If the plastic surface on the ring is damaged the bearing should be replaced anyways.

I know it's been awhile but I thought i would throw an update here. I have since sent my abs module out to be repaired and it has come back. After installing it my trifecta remained but after scanning for codes, I found that I only had one code remaining now: front passenger speed sensor. Excellent!
Ordered a new one but was at the wreckers anyway so I pulled one from another X5. Plugged it in at home and immediately upon startup, all lights gone! Went for a boot around the block and almost immediately the car was angry. Sounded as if the transmission/transfer case were fighting, could barely drive. Unplugged the sensor and went back to before. Turns out, the two speed sensors were different. I do remember the X5 being an 8 cylinder face lift model but I didnt think they would have different sensors but apparently they do :dunno:
So, new sensor will be in this week but I believe it's safe to say that the module rebuild was the culprit all along! thanks for the tips and if anyone needs a rebuild, great company in Mississauga, Ontario: Xemodex. They do all manner of electronic repairs and my module has a lifetime warranty, $400cad.

Thanks for the update! ;)