00283 - ABS Wheel Speed Sensor - Electrical Fault in Circuit

[smilespergallon]

Hi everyone,

Got an "Electrical Fault in Circuit" error with my front left ABS Sensor.

I'll just give you the bullet points of the problem I've been having:

• ABS warning light has been coming off and on intermittently (mostly on) for the last couple of months (along with traction control and tyre pressure lights). When scanning the fault has always been "Electrical Fault in Circuit".
• I hadn't broken anything that I knew about, but I assumed I may have damaged something when replacing the suspension around this time.
• Replaced the ABS sensor, but that didn't fix it.
• Replaced the ABS connector, but that didn't fix it.
• Replaced the ABS connector again thinking that I may not have spliced the wires correctly, or that the eBay connector wasn't up to the job, but that didn't fix it.
• At some point the ABS warning light became permanent.
• Bought a genuine ABS+brake sensor wiring harness from a breakers. Cut the wiring as close to the where it goes in to the wheel arch as I could and spliced it on (see picture below). The brake pad sensor is still working (so I assume my splicing is okay), but didn't fix the ABS electrical error.
• Whilst I had all the wires cut I tested both sides with a multimeter. Was getting some kind of reading from the front-right connector (which is working fine), but was getting nothing from the wires for the ABS sensor on the front left. So I'm not sure why I went ahead and spliced the wiring harness on... guessing I just hoped something magic would happen.

Anyway, I'm assuming the electrical error must be somewhere further up in the wiring in the engine bay, but seems a bit strange as the brake pad sensor is working fine (which is part of the same harness) so I'm not sure what's going on.

So basically, where should I go from here?

Would it be best to get another genuine VAG wiring harness and try replacing the whole thing? If so, is it tricky to follow the wiring? I'm not sure what it's connecting to inside the engine bay or how tricky it might be to replace it.

Alternatively, is there anything else that could be causing the problem?

Any tips or advice would be appreciated. Feel kinda stuck at the moment.

[Octoparrot]

Knackered wheel bearing?

[smilespergallon]

I don't think it would be the wheel bearing as I replaced both fronts around the same time as the suspension.

[Ryanthecarpentermechanic]

Finally someone who has the same problem as me and at the same time!
I’ve had ABS, traction control and tire pressure light on and off for months and has stayed on for past few months and now MOT has just run out i need to sort this asap.

So  i took a look and found the brake pad wear sensor side of the loom was snapped so brought a genuine brake wear/abs speed sensor loom, but like you found has no connector had 4 wires: black, brown, yellow and red. So I thought the easiest way to connect it was to cut the original wire, I cut it just behind the wheel arch grommet, spliced it and soldered it. That didn’t work. Brought a new and genuine sensor… that didn’t work. Read up and people said it could be the solder join creating too much resistance, so i snipped it and heat shrinked the join instead… still nothing. I’m getting the same code (front left ABS wheel speed sensor-electrical fault in circuit)
And I also tested with a multimeter and weirdly had power to the brake pad wear sensor but got nothing from the ABS speed sensor.

At this point I’m getting annoyed debating just getting an auto electrician to find the issue because I cba to take the battery, battery tray and induction kit off to get to the wiring.

[smilespergallon]

Finally someone who has the same problem as me and at the same time!
I’ve had ABS, traction control and tire pressure light on and off for months and has stayed on for past few months and now MOT has just run out i need to sort this asap.

So  i took a look and found the brake pad wear sensor side of the loom was snapped so brought a genuine brake wear/abs speed sensor loom, but like you found has no connector had 4 wires: black, brown, yellow and red. So I thought the easiest way to connect it was to cut the original wire, I cut it just behind the wheel arch grommet, spliced it and soldered it. That didn’t work. Brought a new and genuine sensor… that didn’t work. Read up and people said it could be the solder join creating too much resistance, so i snipped it and heat shrinked the join instead… still nothing. I’m getting the same code (front left ABS wheel speed sensor-electrical fault in circuit)
And I also tested with a multimeter and weirdly had power to the brake pad wear sensor but got nothing from the ABS speed sensor.

At this point I’m getting annoyed debating just getting an auto electrician to find the issue because I cba to take the battery, battery tray and induction kit off to get to the wiring.

Glad I'm not the only one.

I've booked the car in myself to get it looked at. After splicing multiple connectors and a genuine harness I decided to throw the towel in on this one. Hopefully will be fixed by the end of the week.

My only advice in the meantime would be to not disconnect the battery. If you do you will get a power steering assist warning light come on, as I believe it needs both ABS sensors working for it to calibrate itself for some reason. So my car still drives, but the steering feels a little off.

Let me know how it goes if you get it looked at.

[Ryanthecarpentermechanic]

Haha I’ve given up to got an auto electrician booked in to look at it. After being on an off the phone apparently you can get black and grey sensors and seems I have one original black and the new one which is slightly grey which may play a part to it however I’m still getting no power to the left abs and am to the right so sensor is not the problem atm so will see what it ends up being and let you know. Yeah let me know how you get in and what your issue is 👍

[smilespergallon]

ABS issue was fixed today.

The person I took it to just replaced the wiring harness. But whereas I replaced it as it came out of the wheel arch, they cut it further back (closer where it goes in to ABS control unit? Not sure where it goes myself).

Anyway, turns out the black wire within the harness lost continuity for some reason. They've said they've never seen the problem occur that far up in to the harness, as it's usually outside the wheel arch where it gets broken.

It's a bit annoying that I couldn't fix it myself, and that I was on the right track to fixing it as well.

So if you've got the same issue, it might be worth taking the battery out so you can follow where the harness goes in to the engine bay and replace more of the harness with a genuine one from VW.

Part Number: 1K0 927 903R