I reckon the correct Toyota part number for this (right-hand-drive) car is 8954247020 or 89542-47020.
This part is made by Herth+Buss and according to the web has part number J5912045 or EAN 4029416234959, but the only number I can see printed on it is on the lead where it says
Herth+Buss 2973600-1019 - a number unknown to Google!
I just stuck a multimeter across the plug's contacts and that gave me an ohm resistance reading of 1.57 ohms. (I saw a youtube video where the bloke was replacing one - might have been on the Gen3 - and his new one had a resistance similar to mine; the one he took off measured 2-point-something, I think.)
I'll be getting the garage to fit this soon (when they replace a caliper that appears to be binding and causing some unnecessary heat and some very unnecessary intermittent wheel-squeaking) so I don't know if this is going to fix the problem yet. (That goes for the caliper too :-( )
However, the garage told me the wheel teeth are okay, and this part cost me about £40 instead of the genuine Toyota part's £200+, so I figure it's worth a shot.
UPDATE: Replacement part now fitted and I got the garage to give me the old sensor back. It registers 1.64 ohms and varies (just a little bit, somewhere less than 0.1 ohms?) when I flash my keys or something else metal across it.
That doesn't inspire much hope that we've fixed the problem therefore, but what might give me a little bit of hope is that the end of the little metal pin on the sensor does appear to have a little gouge / scratch across it - like it's come into contact with something on its travels.
I'll have to wait till I've taken the car on the motorway to see if it's worked.
(The garage reported that the old caliper was definitely binding, but that pads and disc are still currently okay - so good news on that front.)
FURTHER UPDATE: I had two problems with the old sensor: the car would shudder coming to a low-speed stop as the ABS decided it needed to kick in and out a bit, even with a gentle slow down (come to think of it, the ABS has always been a little eager to kick in when stopping since I first got the car); the ABS warning lights would come and and stay on when I got to (let's say around) 70 mph.) The new sensor has definitely fixed the low speed stopping issue; however, when I get to (let's say a fast) 70mph the ABS light has still come on. (It almost always automatically resets after a restart or two, whereas it used to hand around longer than that before.) My conclusion: Yep, the old sensor was a bit dodgy, but I suspect there's a small bit of damage to the toothed wheel too - probably should have got the garage to replace that at the same time, regardless of the garage's assurances. [Mind you - I haven't checked the price of one!]
