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I recently aquired a 1994 x300 4.0 sovereign with no rear ABS sensors. I have have replaced the sensors with x308 rear ones due to the highly priced originals. I have clamped the sensors down so they cannot move via a bracket that I adapted.

Okay here is the problem. When the car is started the ABS sensor dash warning light goes off as it should. It stays off until I drive the car about 50 metres then comes back on!
Any pointers or experience welcome!
Rob

Hi Rob,

Congratulations on your aquisition of an X300.

It sounds like the sensors are not 'sensing' the ABS toothed rings (on the rear hubs).
I know on the X300 (with correct) sensors, the rear nearside one (if my memory serves me right) also 'tells' the speedo what speed you are doing.

Is the X308 sensor the same length as the X300? Perhaps the X308 sensors are sitting too far away from the toothed ring, to take any readings.
As I have never compared the two, side by side, I can't tell you.

I have fitted an X308 axle (complete) to an X300 and not had your problem - I just had to alter the connections under the rear seat. This does prove that the wiring side of both sensors work.

Yes I agree. The fact that the ABS light comes and then goes off as you start the car indicates that it's going through its checks and that the wiring and sensors pass.
I think that the light coming on when you move off is because you aren't getting a signal from one or both sensors and the most likely reason is that the gap between the sensor and the rotor is too great.
Check to see if the sensor is seated properly? Do you have any OBD diagnostics kit? If you can plug it in and read the ABS fault it will give you a few more clues.

Thanks to both members who offered suggestions and support for my ABS problem.

The good news is I have found a way of using the x308 sensor to replace the over priced x300 sensor. A friend and I made up tooling to set up the correct distance and placement of the rear sensors.

I now have working ABS
Yippee

Glad you got it sorted.
Sounds like something worth sharing in the magazine - fancy doing an article for the forum page?

Pleased you got it sorted.
The sensors are the same part number for X300, X308 and XK8 so should be interchangeable. So I'm wondering why you had to make a bracket for the one you used and why it didn't fit as standard?
The genuine rear sensors LJA2226AA are priced at £107.95 +VAT so if you've found a more economical alternative that would be of interest!

Yes that is common problem that x300 owners have to face when trying to source the sensors and unfortunately I started out from this point myself. The part number you listed is advertised by many as an x300 part. However, it is not! On some of the very late cars there was a similar arrangement but most x300's had a metal shrouded sensor with blades 90 degrees out from the 308 and XK8. The fixing arrangements are also in a different place on the hub. The depth is also different. The original sensors were nearly impossible to remove without destroying them as they rusted into the hub. Many people I have spoken to including technicians who specialise in Jags advised me to swap out the original hubs for the 308 type in order to accommodate the later all plastic sensors, but that would require re establishing the king pin inclination geometry amongst other alignment settings. A search for original sensors (if you can find some new old stock) will show the price around £250.00 a side. So,we have found a way to use the later (much cheaper) sensor, however, it does require significant modifications.

Hi, sorry to dig up an old thread but there’s some great information here.

I’m putting x308 rear hub carriers on my x305 (x300) so I can utilise the later style plastic abs sensors.

Can anyone remember which way to wire the connectors under the rear seat? I have black and brown wires on the old harness but red and white on the x308 harness

Thanks

Marc

There is quick easy fix for ABS sensor on x300. Audi A4 sensor fits and works perfectly. I know my car has them

There is quick easy fix for ABS sensor on x300. Audi A4 sensor fits and works perfectly. I know my car has them

Great information. You would need to expand on the information though. What year and model of Audi A4? Does the wiring need to be modified? Can you take pictures of the sensor out of position and in position? Do you have any idea of price? Does it have to be a genuine part, or are there patterned parts?

Thanks, Peter.

So, this is what I used. The sensor is longer than standard so use a washer to pack out from speed ring. Then cut plug from your faulty sensor, cut plug from new sensor. Connect the wires from new sensor to original jag plug. Connect her up to car loom and away to go. 15 minute job

https://rover.ebay.com/rover/0/0/0?mpre ... 1507770448

This topic has been moved to the 'Brakes' Section.

So, this is what I used. The sensor is longer than standard so use a washer to pack out from speed ring. Then cut plug from your faulty sensor, cut plug from new sensor. Connect the wires from new sensor to original jag plug. Connect her up to car loom and away to go. 15 minute job

https://rover.ebay.com/rover/0/0/0?mpre ... 1507770448

Good information. I knew there would be something similar out there, but finding it.