Okay guys, hopefully somebody can give me some advise because I am seriously getting fed up with this damn truck. It's given me nothing but problems ever since I got it.

I have a 2008 xlt with a 3.0. In the little over 2 years I've had it, most notably in the past year, I have replaced the front driver side ABS sensor 8 times. This is getting extremely cost, and outrageous. Every month or so, the ABS light comes on and the ABS starts locking up when I am driving it. Every time it does it, I have to take it back to the shop for diagnostics, at a rate of nearly 300 a pop. As you can see, the bill for this one damn sensor has become outrageous.

Every time, the same fault code comes up. Drivers front ABS sensor. Putting on a new sensor fixes it, every time, but only temporarily. I have had the tone ring replaced just to make sure that wasn't it, and every single time it's always been the sensor itself.

I have tried various brands, including a couple of OEM at $80 a pop to make sure it wasn't just lower quality parts, and I have the exact same result every time.

I have noticed it seems to do it most noteably during extremely wet conditions, or heavy snow, although a couple of the times it started acting up in the heat of summer. I have even attempted cleaning the abs sensor to make sure it wasn't just dirty, to no avail.

As I mentioned, only replacing the sensor makes the issue go away, and when I am driving the abs system engages at random times if I leave the light on for too long without fixing the abs light.

I need to put an end to this, I have invested so much money just in this last year to this damn thing than I have ever spent on any car.

 

Its obviously not the sensor itself causing the repeated failures. Sounds to me like the sensor/tone ring gap is on the edge of too big. A new sensor works to spec, any degradation over time or by snow/water in the gap pushes it over the edge to failure.

If not that then I'd suspect the ABS controller or wiring to the sensor but neither of those would be susceptible to failure when snow/water introduced.

 

I would agree, but I had the tone ring both checked and replaced, and the same problem still occurs. The only diagnosis that anybody, even Ford has been able to get, is the front driver sensor output fault. Replacing the sensor fixes the issue every time.

It's 4,000 to replace the ABS module, and just spending that money to 'see' if that's the problem doesn't seem very wise, or sensible, since the abs module has never shown any diagnostics codes showing a problem.

It's frustrating this is a repeat issue. It's gotten to where I am just replacing the sensor myself once the light comes on, to save money on labor having somebody else install it for me.

 

Replacing the tone ring won't affect the gap between the ring and sensor, that may come from a slightly distorted hub or a manufacturing defect in the sensor mounting.

TBH I'd get a hub unit from a breakers and swap the whole hub out. Failing that, without swapping parts given there are no diagnostic codes its impossible to troubleshoot further and you are left with minimising the repeated repair cost as you are doing.

One thought - if you remove and refit the same sensor does the problem go away for a while? If so the connector is likely to be the issue but I'd expect that to have been ruled out by now.

 

The Ford Tech(Makuloco) that posts here and elsewhere stated that he has never replaced a wheel speed sensor.

 

I am not sure how that's possible that he's NEVER replaced one, it was a common issue for a while and there was actually a recall for the ABS system at one point from what I read.

Either way, when I replaced the driver side bearing, the shop that pressed the bearing said the hub assembly looked a little 'out of round' where the bearing goes in at, but didn't think it was too bad. If that were the case though, I wonder why it doesn't immediately come back even with a new sensor in. I would think that if it were out of round, it would throw the sensor off even if it was a brand new sensor.

Where is the best place to get new hub assemblies? I've had annoying noises in my front end for a while, and to remedy it I was looking at replacing all the parts in the front-end (the control arms need it anyway), and while I have it apart, i'll replace the hub assemblies on both sides, too. I would consider a junkyard or pull it yourself lot, but then I wouldn't be able to guarantee that one wasn't out of round, either.

 

It's funny you would mention the "out of round" thing...
When the sensor is removed, the hole for the sensor has that appearance, but it's also keyed with a slot. When I did the bearings on my '02 I thought the same thing with that hole. As I recall, the sensor itself is round on the tone ring end and slightly oval at the top.

Bearings are not bad with a .
You will need a hefty slide hammer to remove the old one.

 

I was actually referring to the hole that the hub assembly in bearing go into.

I did notice though that the end of the ABS sensor is flared and the flare is wider than the hole that it goes in. The last time I put it in I had to tap it with a hammer a little bit to get it in the hole.

 

So, after four days of driving with my abs light on, it's no longer constantly on, and really only comes on right after the brakes act up, then goes off again. I've noticed it only acts up under these two conditions:

1.) I turn left. If I brake when turning left, or come off the brakes turning left, I can feel the abs system act up.

2.) If I am backing up I can feel the brakes acting up. After a few minutes of driving straight or no left turns, it goes back to normal and the light goes off.

I also noticed a clunking noise on that side of the car that I heard before I replaced the bearing the last time, so I think the bearing may have went out again, and it's causing the axle to move when turning or backing up, throwing the sensor off. Since the machinist told me the steering knuckle was somewhat out of round, I am going to start by replacing that and the bearing and see if the problem goes away. It's more expensive than just replacing the sensor, but at least it's something different to try.