OK, I continue to battle the good fight against the 3 amigos (or 4 amigos in my case as the '04 D2s also seem to light up the brake idiot light).

Over the nearly 2 years we have had the beast on the road after an engine rebuild, we have replaced the rear passenger ABS speed sensor three times:

First time was a "shorty" that went into the original intermediate connector; that one lasted about 3 months before the lights came back.

Second time was also a "shorty" that went into the original intermediate connector; that lasted about 3 months.

Third time was a "long" sensor wire all the way to the SLABS that was done in conjunction with replacing the rear bearing as well; that lasted about 6 months. (the sensor came with the bearing that purchased from the Utah Land Rover guys).

I get the rough road signal implausible code on the ECU and the bad sensor code on the ABS.

In a moment of delirium, I have also replaced the micro switch in the bottom of the ABS unit itself.

Before I go and buy another long sensor, route it along the frame, thru the firewall and connect it to the SLABS pigtail, I was wondering whether anyone out there has any thoughts about why these sensors might be failing one after the other?

Could it be I am just buying inferior sensors from the wrong vendor?

Could the input for that one sensor be bad at the SLABS itself?

Something else?

FYI, the previous owner had had all of the other three wheel sensors replaced with ones that "home runned" all the way to the SLAB at some point save for the I am having issues with, bypassing that intermediate connector.

 

Having the same recurring issue myself.

 

I would attempt to scrape clean the in-line terminal contacts for the sensors to discard poor connections due to corrosion.
If you have access to a portable oscilloscope, I have checked the waveform of the sensors by a connector under the glove box to determine if they are producing a healthy signal. I did once confirm good signals when the error codes showed ´bad sensors´, also found the amount of grease in the hub and the proximity of the sensor to the reluctor are not critical to impair the signal.

 

Thanks for the idea about cleaning the connectors at the SLABS. I'll let you if that works.

And same for your experience with testing the sensors (I have a lot of stuff but no oscilloscope) relative to grease and hub gaps. I have always wondered about that, but I have a new hub on that corner (less than 10,000 miles).

 

Thanks for the idea about cleaning the connectors at the SLABS. I'll let you if that works.

And same for your experience with testing the sensors (I have a lot of stuff but no oscilloscope) relative to grease and hub gaps. I have always wondered about that, but I have a new hub on that corner (less than 10,000 miles).

 

The connectors I suggest to scrape clean are at the sensors, not at the SLABS. But if your vehicle has been underwater, will be beneficial to ensure they all make good contact.
What I did by the SLABS compfuser is connecting a oscilloscope probe.