Front Nearside ABS Sensor Faulty

[Chief Brody]

Hi all. Hoping someone can point me in the right direction with this. My Bongo has been living in a relatives driveway for a few months due to a family matter. Before that though, the ABS 4WD light came on whilst I was driving. Not all the time but most of the time. It will be due an MOT next week so trying to get this sorted (as well as other things) I have checked the fault code and got an error code of 12 which points to the front passenger sensor. I have resigned myself to having to pay the £180 for a new sensor but just wondering how easy the front passenger sensor is to change.

I know I will destroy the current sensor when removing it but will the new sensor fitting be straightforward? I've never even seen an ABS sensor. Will I have to remove the wheel or jack up the Bongo? Is there a chance that there could be faulty wiring rather than the sensor? When I think back to when it started, there's a chance that it was when the front passenger wheel was changed. It is the same wheel as the others but is there a chance that something was dislodged when the wheel was fitted? Thanks for any help offered.

[Chief Brody]

Will keep this updated as I go along. I've purchased the new sensor. I think I found the sensor under the leisure battery tray on the left, behind the headlight. Unfortunately the bolts for the tray have seized. Will try and get in later. Hoping I can replace the sensor from under the tray. Not sure why the light doesn't come on from the start of every journey. Took Bongo back home from relatives and the ABS light didn't come on once. Then this morning it comes on after a couple of minutes on way to work.

[g8dhe]

Have you tried cleaning the connector ? I had this problem a while ago and it appears to have been moisture penetration into the connector.

[Chief Brody]

Thanks. Not tried cleaning the connector yet as I can't get my hands in until I've removed the battery tray. I'll have another go tonight.

[Chief Brody]

Meant to ask, is it possible to replace the sensor myself from under the bonnet?

[Bob]

Don't know if a spray of contact cleaner might do it? [-o<

https://www.carparts4less.co.uk/p/wd-40 ... lhEALw_wcB

[g8dhe]

I came to the conclusion that as the connectors down under the vehicle were all good quality waterproof style ones it wasn't going to be ingress of moisture from outside that was causing the problem, rather it was condensation within the connector shell due to the protection being waterproof but not gas proof.
This condensation was then causing small amounts of corrosion on the pins inside the connector shell, vibration, temperature changes or even simply handling of the connectors would be sufficient to disrupt the corrosion and "cure" the problem on a temporary basis - hours to months timescales. After a few weeks of repeating problems I ended up disconnecting, cleaning, spraying and then reconnecting the connector that was causing grief and since then it has never returned.