I've learned a bit about the R51 wheel sensors (not by choice) and thought I'd resurrect this old thread to share.
Problem first started during a heavy snow fall. Driving I hit a bump. ABS, VDC and SLIP all came on immediately, followed shortly by the 4x4 light. The 4x4 status indicator LCD also went blank.
Step 1: Have it scanned, yep it's the front right abs sensor.
Step 2: Wait for temperature to rise (no garage) and take off wheel. The problem is two torn wires and a dangling ABS sensor plug, with barely enough wire left on the plug to make a connection. Soldered it back together, taped, shrink wrapped etc. Reset warning lights, ABS sensor still comes back as bad, along with steering angle sensor.
Step 3: Maybe sensor is also bad? Dealer wants $300, Amazon $49, tough choice. Replaced sensor. A bit more of a PITA then I expected, as rotor has to come off hub. Reset warning lights: ABS sensor still bad.
Step 4: Drink.
Step 5: Looking at the ABS sensor description, part number works for front left OR right?!
The parts should be mirror images of each other? In my naivete I had assumed black wire goes to black wire through the plug prongs (and white to white). I was wrong: Once I reversed the polarity at the plug everything worked as it should
TLDR: R51 front ABS sensors are polarity sensitive and polarity of passenger side is reversed at the plug connection.
#themoreyouknow