ABS and Break light on

[Puremuscle]

Have an issue with my ABS and Brake light being on. So, the problem started out with my transmission having a 3-4 and overdrive shift problem. After reading here and understanding how the shift points worked, turned out to be my VSS on the speedometer cable; it was bad. Switched it, truck shifted as should but then my ABS and brake light came on after driving a day or so. I noticed I hit a bump and it went off but came back on after a minute or so. I checked to see if I may have disconnected or loosened a plug by accident but all the connectors, speed sensor at rear axle, connector at ABS valve, and for good measure connector in engine compartment on driver side wheel well. fluid level fine though i did notice the connector to the master cylinder reservoir pulled out. cleaned the tip pushed it back in, light still on. I don't see how changing the VSS would cause the issue but that's why I'm here. Maybe it could. Any ideas or suggestions would be helpful.
Thanks

 

[J_C]

Back when I had an ABS issue on my '98 and pulled the fuse to disable the ABS, it set a code that I had to use a scan tool to reset, putting the fuse back and disconnecting the battery did not get rid of it. However even with the code set, ABS continued to function. Don't know if that applies to yours but thought I'd throw that out there.

Here's a topic on pulling ABS trouble codes:

How to: Pull trouble codes on 4WABS, very simple

Pull trouble codes on a first Gen Explorer is very simple, only need one jumper and one test lamp or analog voltmeter, or if you no have these parts can use the ABS ligth in the dashboard. - In the ABS test connector (engine compartment, RED CONNECTOR, not same as EEC-IV test connector) install...

www.explorerforum.com

Within that topic, what the codes mean:

How to: Pull trouble codes on 4WABS, very simple

Pull trouble codes on a first Gen Explorer is very simple, only need one jumper and one test lamp or analog voltmeter, or if you no have these parts can use the ABS ligth in the dashboard. - In the ABS test connector (engine compartment, RED CONNECTOR, not same as EEC-IV test connector) install...

www.explorerforum.com

In my case it was my hubs going out. I had a fault, replaced hub, was good for months, then the other front hub did same. If you're still on your original hubs, I'd wonder about them, unless it is a RWD model then the sensor isn't in the hub but AFAIK, external behind the rotor, and then if the tone ring on the rotor gets too corroded, that can cause it.

You can also measure resistance for the speed sensors at their pigtail connector and see if it's the same at the ABS controller connector, and see if they produce a low AC voltage when the wheel spins.

That you had it go off when hitting a bump, makes me wonder most about a bad connector or frayed wire shorting out or losing conduction. I wonder if it's just highly coincidental since it operated fine for a day after the repair.