Over 75+ Mph ABS Light Comes On

[DeadEye200321]

Hello,
I've been having some trouble with my Ranger for a little bit now. I have a 2004 4.0L V6 FX4 Off Road XLT Ranger. When I am driving and only when my speed is 75 mph or above the ABS light and Brake light will sometimes come on, this does not happen every time I exceed 75 mph as it is inconsistent but it has been inconsistently happening for a little bit now and I want to fix it. It appears to be a soft code as when I turn the truck off, the ABS and Brake light turn off on the dash. Below is a photo of the codes I was able to get read when the lights came on:

I checked each sensor making sure they were in tack and they were (I inspected the outside but I did not take the bolts off and completely pull them out), I also checked the wiring as far as I could until they merged with the engine wiring harness and it all seems fine as well. I cleaned my battery terminals from corrosion thinking maybe it was possibly a grounding issue and that did not fix the issue. The odds of all 3 sensors going bad at once I feel are slim to none and am not sure where to go from here as to what to check/replace/repair. I believe I have listed everything I have tried and all the details about what is happening. Any help would be greatly appreciated. Thank you!

 

[Curious Hound]

Not sure. Wheel bearings all good?

Gotta admit. When I get up to 75mph in my Ranger, I’m so giddy with excitement that I sometimes become incoherent, too.

 

[SenorNoob]

Sounds like the abs sensors just can't handle that speed...

 

[DeadEye200321]

Sounds like the abs sensors just can't handle that speed...

They have in the past though with no problem, this only started to happen maybe within the past 5 to 6 months so I know they can handle the speed no problem.

 

[DeadEye200321]

Not sure. Wheel bearings all good?

Gotta admit. When I get up to 75mph in my Ranger, I’m so giddy with excitement that I sometimes become incoherent, too.

Yeah the wheel bearings do appear to be fine, little bit of left and right play but that's because one of my ball joints is going bad but that shouldn't affect the abs sensors. My truck can handle 75 no problem, fastest I've ever taken it was 90 but I have no need to go faster than that for my safety and the vehicles sake.

 

[sgtsandman]

It is possible that there might be a little bit of rust or dirt build up on the tone rings or the sensors. If I remember correctly, the sensors are magnetic. So maybe cleaning them will help?

 

[Uncle Gump]

Monitor live data for each sensor while driving at speeds that the fault happens. You might be losing a sensor or the ECM sees a speed mismatch.

I've seen this happen at slow speeds before and it will activate the ABS when you hit the brakes.

 

[Curious Hound]

Make sure all tires are the same size.

 

[lil_Blue_Ford]

With it saying that the rear sensor isn’t reading at all, I’d guess there may be some metallic fuzz on the sensor and at higher speeds it’s enough that it disrupts the signal.

That said, I’ve never been able to pull a sensor, front or rear, and not have it break.

Also, if the sensor in the rear axle has picked up metallic fuzz, or chunks, you’re going to want to open up the diff and figure out what’s going on…

 

[DeadEye200321]

It is possible that there might be a little bit of rust or dirt build up on the tone rings or the sensors. If I remember correctly, the sensors are magnetic. So maybe cleaning them will help?

Potentially, Ill clean them after work and see if that might fix it.

 

[DeadEye200321]

Monitor live data for each sensor while driving at speeds that the fault happens. You might be losing a sensor or the ECM sees a speed mismatch.

I've seen this happen at slow speeds before and it will activate the ABS when you hit the brakes.

I sadly do not have the equipment needed to monitor the live data and those obd2 readers that can do that are pretty costly.

 

[DeadEye200321]

Make sure all tires are the same size.

Tires have not changed since I got the truck, probably isn't that LOL

 

[DeadEye200321]

With it saying that the rear sensor isn’t reading at all, I’d guess there may be some metallic fuzz on the sensor and at higher speeds it’s enough that it disrupts the signal.

That said, I’ve never been able to pull a sensor, front or rear, and not have it break.

Also, if the sensor in the rear axle has picked up metallic fuzz, or chunks, you’re going to want to open up the diff and figure out what’s going on…

You might be onto something with this, thinking back, I did replace my spider gears around 6 months ago because I shredded them to pieces. I'll take my rear sensor off and see if that might be the issue. Cause it's very possible some metallic fuzz got on it when the gears shredded and even when I did extensively clean the diff housing, I might not have gotten the sensor cleaned. I'll let everyone know if this works!

 

[sgtsandman]

I sadly do not have the equipment needed to monitor the live data and those obd2 readers that can do that are pretty costly.

There is a free program called Forscan for computers and Forscan Lite for tablets and phones that can do it and you can get a free upgrade for a couple of months for free as well. The adapters that plug into the OBDII port aren't that expensive. They list the recommended adapters on the website.

 

[don4331]

Tires have not changed since I got the truck, probably isn't that LOL

The sensors are measuring the difference between the wheels to determine if you one (or more wheels) have an issue (focus is on braking, but it's checking all the time). So, if for whatever reason (wear, tire pressure, size) there is sufficient difference, the module flags it. Therefore, if one tire has worn more than other (poor alignment, etc); then when you fast enough you can trigger the flag.

That said, if you have had issues with the spider gears, I would start with the rear sensor (the one on my daughter's '02 Explorer "wore out" <lost ability to sense> ) and was causing ABS issues. Our vehicles are getting over 20 years old and that's longer than Ford planned for some of the parts to last.

Cleaning all the debris out of the axle tubes is PIA. Remember, oil goes all the way to the wheel bearings...