I would greatly appreciate any help or insights. I'm several attempts into trying to resolve an ABS sensor related fault on my '01 Disco.

Initially the 3 amigos and brake light came on in the instrument panel. I pulled the codes and found three faults: 1 - 4045 Sensor Left-Hand Rear (Sensor Air Gap too Large); 2 - 4065 Sensor Left-Hand Rear (Sensor DC Failure, Broken Wire, Sensor Impedance Too High/Low); 3 - Sensor Left-Hand Rear (Intermittent Sensor Output During Driving, Broken Wire). I purchased a used ABS Sensor (the older type that plugs into the wiring harness 16" or so from the hub assembly) and installed it. I cleared the codes, but the lights were back on within minutes of driving.

Next, after reading that Land Rover had reworked the ABS sensor to eliminate mid-harness faults, I installed a new sensor and overlay harness that I spliced into the multi-plug inside the cab of the truck only inches from the SLABS module. I cleared the faults, and, for about a week, it looked like that had done the trick. Then the lights came back on. I pulled the codes again, and I had all the same faults.

I pulled the tire off intending to inspect the hub assembly and the tone ring, and I saw a glob of grease partially covering the ABS sensor. It had worked its way up from inside the hub assembly. I removed the ABS sensor and found a broken rubber O-ring. After replacing the O-ring, I tried to clear the faults, but fault 4065 (Sensor Left-Hand Rear (Sensor DC Failure, Broken Wire, Sensor Impedance Too High/Low) would not clear. I drove it a short distance, but that one fault code still wouldn't clear.

I didn't have any of the actual terminal ends that attach to the sensor wires and insert into the multi-plug (to eliminate the possibility of a bad connection at the splice), but I checked and re-did the connections and don't see anything troubling.

There was no play in the hub assembly that would indicate a bad bearing, nothing else that seemed out of the ordinary, and I didn't see anything of concern when I removed the ABS sensor and visually inspected the tone ring.

The only thing I can think to do now is replace the hub assembly in the hope that some condition within the hub assembly is causing the sensor fault, but how likely is it that there's some damage to the tone ring inside the hub if there doesn't seem to be an issue with the bearing or the assembly itself? I'd really appreciate any helpful suggestions or insights.

 

WarrenZ - It sounds from your description you have multi issues going on. I also had those same codes and noticed a fair amount of grease on both hubs. I went ahead and replaced both hubs with the Brit Part replacements from LRDirect. They came with new sensors. After installing and hooking them up, all the ABS codes you described went away.

However, I also did the Option B as shortly afterwards my code reader said the shuttle valve was bad.

 

So, I'm still trying to crack the code on this. I went ahead and replaced the hub assembly a couple weeks ago. The new hub assembly came with a new sensor, though it was the older kind of sensor that plugs into the main ABS harness near the hub, so I plugged it in and reconnected the old terminals at the SLABS. That worked for about a week - again, then the 3 Amigos and the "Brake" light came back on. I pulled the ABS codes and found 2: (1) 4045 Sensor Left-Hand Rear (Senor Air Gap too Large), and (2) 4085 Sensor Left-Hand Rear (Intermittent Sensor Output During Driving, Broken Wire).

Given that I had plugged the new sensor into the old wiring harness, I figured I needed to rule out a mid-harness fault, so I carefully spliced the new sensor into the overlay harness I had run several weeks ago and reinstalled those terminals into the multiplug at the SLABS. No luck. I tried clearing the codes, but I wasn't able, as the computer was showing 4065 (Sensor Left-Hand Rear (Sensor DC Failure, Broken Wire, Sensor Impedance too high/low) as a current fault. After driving it for a few minutes, 4085 (Intermittent Sensor Output while driving, broken wire) had returned as well.

Just for kicks, I exited the ABS section and checked for fault codes in the ECU. I found one - "Rough Road Signal Implausible - Value Not Plausible. Fault Present and Static."

In all other respects, the truck seems to be functioning normally. A while back I had ABS codes related to the shuttle valves, but I replaced the modulator and bled the system, and that's been fine ever since. Had to replace the throttle body heater plate due to some minor coolant leakage. The truck idled rough when I first started it after that procedure and gave me a misfire codes, but that condition seemed to resolve itself quickly and hasn't returned.

Still looking for answers. I'd appreciate any thoughts...

 

could be a short somewhere in the harness or you might have to hardware them to the bcm