ABS Help!

[dburney]

Hi all! Coming here as a last resort. I have an 02 Ford Explorer 4.6L V8. Recently, ABS, 4x4, and check advtrac lights came on. Had the 4 wheel sensors replaced, lights are still on. When driving, I hear grinding before my sensor "kicks" out and advtrac light comes back on. Few questions... 1. Does my car have a rear differential speed sensor and 2. Could this be a speed sensor issue? With shops hurting for cash, I have had several different reasons as to what could be wrong... any insight is helpful and TIA!

 

[Fix4Dirt]

welcome to EF!! if you hear grinding, is it the hubs? the speed sensor could cause issues, but i think that its something in the hbs and stuff that affects abs, but jmo!

 

[dburney]

welcome to EF!! if you hear grinding, is it the hubs? the speed sensor could cause issues, but i think that its something in the hbs and stuff that affects abs, but jmo!

the grinding isn't constant. it stops shortly after I start going. I had the front 2 hubs replaced but not the backs. noise sounds like its coming from the front

 

[Fix4Dirt]

not too sure on thsi one, but diffy? if you turn the halfshaft, does it feel like its binding? hows the oillevel?

 

[drdoom]

2002 model has three channel ABS, as you suspected one at each front wheel and the third is in the rear differential, up on top.
Four channel ABS was not available until 2004 or 2005, as far as I know. I have factory manuals for 2005 model year, and the above information was taken from there.

 

[drdoom]

Those sensors l believe are Hall Effect, so hooking up a multimeter and waving a piece of steel past it will tell you if they are any good. It is a simple test, and an old analog meter works best, as you can watch the needle sweep in real time.
FYI often times, the metallic detritous from bearing wear/failure is attracted to the sensors, as a Hall Effect switch contains a magnet. This detritous will interfere with the signal.
Cleaning can help, probably mostly for diagnostics and maybe not for a long term.
Anyway, pull them out and have a look.
Lastly, remain mindful of the provenance of any wheel bearings used.

 

[drdoom]

But you have numerous malfunction indicator lamps illuminated. So the trouble codes can be read, although some are proprietary and not visible to a run-of-the-mill scan tool. But with the proper interface (many here use a highly functional open source software), reading the live data on the wheel sensors is simple, and the way to go. To actually know what to replace, and eliminate the guesswork altogether.
To find the noise, you must raise the vehicle and run it. Driving it and listening works, but not always. Same for raising the vehicle, doesn't always work. But you are driving and trying to make that determination, I suggest another method.

 

[dburney]

Update, wheel sensors replaces, speed sensor replaced, shift control motor replaced. The lights went off when I installed the shift control motor, but not for long... back to square 1

 

[Fix4Dirt]

whats the code? just curious, as im out of ideas on this at the moment... will update if i think of naything else

 

[Izzythoed]

I had the same issue on my explorer I just replaced the whole front new suspension wheel bearings with abs sensor light finally went away

 

[dburney]

whats the code? just curious, as im out of ideas on this at the moment... will update if i think of naything else

Not sure. I’ll have to pull it. Gonna try replacing the module next

 

[Fix4Dirt]

Not sure. I’ll have to pull it. Gonna try replacing the module next

imo read codes before module, usually replacing a module is firing the parts cannon imo

 

[dburney]

I had the same issue on my explorer I just replaced the whole front new suspension wheel bearings with abs sensor light finally went away

Wheel bearings is next. Running out of options at this point and super frustrating

imo read codes before module, usually replacing a module is firing the parts cannon imo

ran the codes on my reader, mechanics reader and at autozone. All 3 are not pulling any code for the ABS. Unplugging the module helped but not for long

 

[LMHmedchem]

Is your truck RWD/4WD/AWD?

Wheel bearings is next. Running out of options at this point and super frustrating

You mentioned that you already had the front hubs replaced. The hub and wheel bearing is a single assembly on these so you have already replaced the front wheel bearings where you think the sound is coming from. Do you know what was used for those parts?

If you have 4WD/AWD there is a carrier bearing on each side of the front differential that you might want to look at.

There are some cases where temporarily disconnecting the front differential, removing the front CV axles, or both, can help when trying to diagnose a problem like this. Look into that carefully before going that far though.

LMHmedchem

 

[dburney]

Is your truck RWD/4WD/AWD?


You mentioned that you already had the front hubs replaced. The hub and wheel bearing is a single assembly on these so you have already replaced the front wheel bearings where you think the sound is coming from. Do you know what was used for those parts?

If you have 4WD/AWD there is a carrier bearing on each side of the front differential that you might want to look at.

There are some cases where temporarily disconnecting the front differential, removing the front CV axles, or both, can help when trying to diagnose a problem like this. Look into that carefully before going that far though.

LMHmedchem

 

[dburney]

Not sure what the above has to do with ABS, 4x4 high flashing, and adv trac warning light but I’ll check em out

 

[drdoom]

Just keep throwing parts at it then...

 

[drdoom]

imo read codes before module, usually replacing a module is firing the parts cannon imo

+1

 

[dburney]

Just keep throwing parts at it then...

yea I mean that's what I have been doing since I got it. Started with brakes, then cv axles on both side with hubs, plugs and wires, gone through essentially the whole ABS system (4X4 module is next). With no codes pulling from the ABS warning light, I really have no choice but to keep throwing parts at it lol. The sound is coming from the back with the check advtrac warning light and 4x4 high (flashing) comes on. The hubs were replaced for a different issue, my lights were not on when these went out on me. To me, it seems the module is on the fritz. When I disconnected the module for ~15 min, everything was off for about 45 min drive. The next morning, it was all back. So my gut tells me that is the issue. Also considering the ECU may be on the fritz. So possible next on the list if module replacement does nothing.

 

[dburney]

+1

ran codes with 3 different readers, no codes are pulling from ABS