Morning All!

[jonathondesmond]

Just had a fun weekend diagnosing and replacing my front ABS speed sensors. It lead me to Forscan and, eventually, to here.

It was an odd story:
1) I had a flat tyre just before Xmas - driver's side rear.
2) I put on the factory spare and thought no more of it.
3) The next day, driving to work, the ABS triggered for no reason at all - twice, about half a second each time - then went into fault (dash lights lit up: ABS, Traction and Check Engine)
4) As a result, ABS no longer worked (no surprise there) - but nor does Cruise Control (this is normal, but surprised me)

Diagnosing it with my generic OBDII reader just gave me U0418 "Invalid Data Received From Brake System Control Module". Fortunately I had a spare bluetooth ELM327 kicking around that, in conjunction with Forscan on Android, gave me more detail - Front Right ABS Sensor failure.

Now trawling through Newranger.net I realised that failure of this particular sensor is fairly common, so no biggie - after prevaricating a little bit (reset DTC to ensure that the error persisted, check the wiring loom at front and rear including the Y connector near the rear diff etc) I resolved to replace the FR sensor this past weekend when I had a chance.

However, in the process of checking, I decided to unplug and test the front left sensor (to check voltage levels from the ABS control module - checking that the loom to the right sensor was OK so I would be sure the fault was with the sensor and its wiring). This went fine - but the next day the left sensor also went into error mode.

Ordered both sensors from the local stealer (£68 each, should have picked them up in Oz over Xmas), fitted them and all is now well.

However, I couldn't help myself - I stripped back the insulation on the removed sensor (near the sensor end) and one conductor - white - is corroded. The other is fine. No sign of insulation failure (well, before I stripped it back off, anyway).

It's almost as if the sensors were assembled with poor quality wire at the factory. Could possibly explain the failure of the left sensor after I started messing around with it too - if the cable was dodgy then unplugging it and moving it around could have sent it over the edge.

Fairly easy to replace the sensors, although the left one wasn't coming out of the hub without a fight - wound up removing it in three bits with a screw extractor. Felt like an old time surgeon putting the pieces back together to check there was nothing left in the patient.....

Most annoying experience - but quite educational.

[saeb]

Thanks for the write up Jonathon. Glad you got it all sorted in the end.

Maybe make a new post in the Wheels and Tyres area and copy this info across, it may be of help to someone at some stage.