Dirty abs sensor cleaning help

Bobbby2000 · January 1

Gs450h. Second hybrid lexus . Love it. However I have a VCS and ABS light on - plugged in to techstream which said debris on rear right abs sensors. Removed sensor and replaced it . Wire brushed as best I could . Reset codes. All fine for 5 mins then lights back on. Same codes . My question is how can I clean Inside more ? Is it possible to remove the sensor again and clean through the hole ? Or do I need to disassemble the rear hub ?

ColinBarber · January 1

I would try taking out the sensor and shining a light whilst you rotate the driveshaft to check the teeth before stripping down the hub. One or more may be damaged which means you will need a new driveshaft.

Bobbby2000 · January 1

Thanks . New driveshaft or outer cv joint ?

ColinBarber · January 1

18 hours ago, Bobbby2000 said:

Thanks . New driveshaft or outer cv joint ?

Depends on vehicle. You don’t state what age your GS is and your profile states a 2008 RX. Often Lexus only sell a complete driveshaft with attached CV joints and you need to be careful with aftermarket ones as they sometimes expect you to swap the ring from the old one.

Hopefully there is just some metallic dirt in there that can be cleaned out.

Bobbby2000 · January 2

It's a gs450h. I joined when I had an rx and haven't changed my car spec

steve2006 · January 2

As Colin suggests I totally agree, the toothed rings on the hub or “Reluctor rings” to give them the correct name have been known to crack due to age and exposure to the elements or a build up of rust and crud between the teeth which then leads to error codes due to a change in the critical air gap between the ring and ABS pick up coil.

Again as Colin advises remove the ABS sensor and using a torch look down the hole looking for crud and damage whilst slowing turning the hub.

Also if you have a multimeter measure the resistance of the sensor, if it reads open circuit it’s duff.

The reluctor rings are generally available to buy as a separate item just google “Lexus Reluctor rings”

Paul Brooksbank · January 2

The reluctor rings on the Rover and Smart cars used to crack. This caused a gap in the teeth that threw up a spike in the reading going into the sensor. Essentially, the sensor is a proximity sensor that reacts to each tooth passing it, setting up an "on/off" signal, or sine wave similar to a DC current reading. Any difference in the sine wave indicates to the system that the wheel is locking up or spinning, thus activating the ABS.

The trick on the Smart was relatively simple in that you removed the broken ring, cleaned up the hub, then fitted the ring back with epoxy resin, holding it in place (closed) until it set. Then give it a light coat of Hammerite and all was good.

If this link works, it gives the instructions https://www.evilution.co.uk/?s=Reluctor+rings

Bobbby2000 · January 2

Update. I drove the car whilst my mechanic mate was plugged in to techstream. All the abs sensors are reading accurately with accurate speed so I assume the rings are good

Bobbby2000 · January 2

Also for love nor money I can't find reluctor ring for the transfer of a gs450h

ColinBarber · January 2

what error code are you getting? The waveform only has to be out a bit for it to throw the foreign object error and you potentially need an oscilloscope to see the error.