Hello all, new the forum! Hopefully, I'm posting in the right spot.

I have a 2011 Ford Explorer Limited with 131,000 miles on it. ABS and traction control lights began coming on intermittently, along with the "Service Advancetrac" warning in August. Didn't have a code reader to read the ABS system at the time so I did a preliminary check of the brake fluid and fuses. All fuses checked out but brake fluid was a smidge low...nothing drastic. I added maybe a 1/8 cup of brake fluid that, yes, had been previously opened, probably for a couple months.

But the warning lights went off!

But I knew it couldn't be that easy. Sure enough, they came back on a couple days later. By this time though, I had already purchased a FD Linker and Forscan Lite for Android with the licensing.

Plugged in the code reader and it threw a C0037:01-AB, Left rear wheel speed sensor (GENERAL ELECTRIC FAILURE) . Easy enough, replaced the sensor, cleared the codes, and the lights went off again! The sensor looked damaged so it seemed like the likely culprit.
Nope! Lights came on once again in about a week or so. Plugged in the scanner again, this time its throwing the same C0037 code....AND C0034:01-AB (GENERAL ELECTRIC FAILURE) for the front right speed sensor as well! Looked at live data and sure enough, front right and back left showing nothing.

Now I'm at a loss.

Put it on my neighbors lift to check out wiring and inspect tone rings. All looked to be intact. Cleaned the tone rings while I'm under there, hoping maybe metal shavings were interrupting the signals. Take off the lift, start it up, codes are gone again! Not only are the codes off but the live data is showing all wheels registering!

But not for long. They came back on the next day

But now, the "CHECK BRAKE SYSTEM" and "SERVICE ADVANCETRAC" warning, along with all associated lights are on.

Its now throwing U3000:49-68, for ABS module (Internal Electronic Failure) along with C0037:01-AB and C0034:01-AB codes.

The U3000 code, however, is intermittent and clearable, while the C0037 and C0034 sensor codes are now hard codes that will not reset.

I've tested the sensors with a multimeter for resistance. Front right .99, front left 1.00, back left 2.4, back right 1.9.

From there, I plugged the rear right wiring into the left rear sensor. It read speed on live data.

I tested the DC voltage on the front sensors (too short to swap) and both sides read voltage while turning wheels.

All the wheel speed sensors are working and wiring seems to be intact

Sooooo...I guess my real question is...

What's the likelihood that my ABS module is bad? With it being an intermittent soft code?
Could bad brake fluid cause these issues?
Also, yes I've left my battery disconnected all night and those 2 hard codes will not go away no matter what I do.
Am I missing something?

Please help

 

Not really, there is a dedicated forum for Explorer.

Very first thing to check is your battery cables (both red and black) make sure they are connected to the battery post to correct torque specs. Modules do not like intermittent or unstable power supply, and ABS module is most sensitive on that.
vLinker FD with Forscan lite can only do so much and you know it doesn't have bidirectional support or module adaptation reset. If you need to do more I recommend Foxwell NT510 Elite w/ Ford software (includes Ford Lincoln and Mercury), only thing you probably can't do is ABS module programming if you decide to buy a used one on eBay. To program a module you need to get Forscan full version on windows, or a shop or dealership with IDS.
What I would do is to recheck all the wirings especially when you already cleaned all the sensors. Use NT510 Elite so you can run active tests then reset ABS adaptation. And last resort look for ford PCM module repairs on eBay, they probably repair ABS module as well. Contact the seller and fully explain the problem, if they can't fix they won't take your money. Good thing about a module repair is you don't have to program it.

Cars in the 80s or 90s probably. A 2011 Ford Explorer, you can't just disconnect the battery to reset most modules, you need NT510 Elite or Forscan Full version on windows. The modules that you can't disconnect battery to reset are those with non-volatile memory onboard. Say you disconnect the battery and your radio presets are reset, then your radio, even if it's connected to a module (like ACM), doesn't have a non volatile memory. The module itself makes communication friendly with a capable scanner with bidirectional support. Active test and bidirectional support, for example, you can tell NT510 Elite to turn on the reverse lamps on your behalf for a duration, say 15 seconds, without having you to shift to R position while it's still in P position, because on the backend NT510 Elite will communicate with your BCM module.

If you purchased your vLinker FD within 30 days from Amazon or eBay I suggest you to return it and get OBDLink MX+ instead, it's pricey and perhaps the most expensive adapter on the market. What's so good about it is the OEM-specific enhanced diagnostic support for many car makes with no additional cost. For instance, Ford, Lincoln, Mercury, Mazda, Nissan, Infiniti, Toyota, Lexus, Scion, Chrysler, Dodge, Jeep, Ram, Fiat, Mitsubishi, GM, Honda, Acura, Hyundai and Kia. If you own just a Ford, then VLinker FD is probably alright. If you get any other OBDLink model other than MX+ then you have pay extra on the car makes. You still can use Forscan Lite with the MX+ adapter. The OEM-Specific enhanced support is the DTCs that you can't get with a generic OBD2 scanner, you also can view a lot more live data, many pids are preconfigured but you can still add custom pid to retrieve more. This is what's missing on VLink FD + Forscan Lite if you care more about live data.

BTW if you decide to get NT510 Elite, go to aliexpress, you pay 50-60% of the price than Amazon around $90-$120 w/ one free software, select Ford. Select to ship from China instead of US warehouse is cheaper, and there is no surprise trump's tax and duty fee upon delivery, everything is paid at checkout upfront.

 

Some things of which you should be aware;

ABS runs a pre check the minute you turn the ign on. If circuit is not complete due to open in system or electrical fault, light and code will come on.

Codes on later models can no longer be easily cleared with reset. Vehicle system has to run through drive cycle verifying system function is correct, and if repair was correct , code will clear itself.
If not, light and code stay.

 

I truly appreciate the responses! All very good info, thank you!

I did check the battery cables to ensure a good connection, they're good. I actually went ahead a replaced the battery for good measure, hoping maybe an intermittent drop in voltage was causing the ABS module to act up. I've driven it plenty enough, hoping the codes would clear, and it has made no difference.

Anyone think theres a possibility that the sensor I already replaced isn't compatible for some reason or is causing an electrical issue?

I just cant seem to wrap my head around the fact that it started with one sensor, and now its throwing codes for two. Two sensors of which dont appear to share a connection, except at the module itself.

Also, I should probably mention the idle/starting issue it has as well. Possibly unrelated, as it began quite a while before the ABS issue.

But, it has a intermittent issue with a slow start as well. Just cranks longer before it turns over.

Then the idle also seems to be off or bogged down at times. Like when I turn the ac on, or simply roll down a window, it bogs down. Almost to the point that I feel like its going to die out at times, but hasn't. This is all still happening after the battery replacement as well.

Like I said, I truly appreciate any and all knowledge anyone is willing to give me, thank you!

 

There is a good possibility all your problems are coming from a poor connection in the wiring to the components of the ABS and some other systems as well.

The tell tale clue is under power load things are not working as they should.
What you might consider doing is; start checking every connection from the battery to where it supplies power to all systems incl fuse panel.
Also don't forget positive side power is only half of the circuit. The other half is the GROUND connections. You can't correct any connections just by looking at them .
They must be removed/opened . cleaned and reconnected. If you do that, you may or may not know which connection was faulty, but the problem can be gone.
You might also consider removing the ground(-) cable from the battery when you go removing other wires that could spark and create problems. Just reinstall the ground cable when finished. This can take some time, go slow and be thorough.

In the process of removing wires and cables , you might lose some computer programming like radio stations , shift scheduling When you feel you are done, you can start the engine, but don't touch the throttle pedal ,the PCM will automatically correct any possible high idle speeds. Regular driving , around the block will help shift scheduling with just normal driving.

 

Thank you for this. This is what makes the most sense to me as well. And the be completely honest, the answer that I didn't necessarily want to hear but needed to hear...the dreaded electrical rat race lol
Which after further research, seems to be a common issue with my year/make/model.

So, let the rat race begin

I'll post with updates hopefully sooner than later! Thanks again!