96 4.0L ABS motor comes on/no ABS light?

[jvorrius]

Hi,
I have a 1996 Ford Explorer Sport 4x4 with 151K.

I see this is a common issue on this board but with my problem the abs light does not come on during the problem.

About a month ago the abs motor would turn on when coming to a complete stop. Typical brake studdering at low speed stop. The ABS light did not come on. The truck was due for some maintainence and brake servicing anyway, so I replaced the front pads and rotors. Also my rear axle seals were leaking so I replace them. Also, the rear rotors, brake pads and parking brake shoes were replace at that time. The brake studdering problem is still happening after the work has been done.

About 4 years ago, I had the same issue with the brake ABS motor coming on but the ABS light lit up. Tested the 2 front ABS sensors and the ohm reading was way out of range. I purchased them from Ford and replaced them. The problem went away and I reset the light.

The problem now is the same but with no ABS light lit and the ohm readings on both front sensors are at .4 ohms. I also removed them and cleaned the ends. I'm pretty sure that is within range for a 4x4.

Any help would be appreciated.
James

[TeamExploder]

Try a computer reset, just unhook the negative battery terminal for 10-15 minutes thats normally how long it takes to reset the computer. next thing I would check out them sensors again and try giving them a cleaning. Have you checked your dash lights to see if maybe the abs light didn't just burn out?

[jvorrius]

Hi,
Thank you for replying so quick!!

The ABS dash light does work when you turn on the ignition key.

I will disconnect/reconnect the negative battery terminal and see if that helps. I know when I was doing all of this work the battery was disconnected bu I'll give it a shot.

One thing i forgot to mention was that when just going through a parking lot with my foot off the brake and gas you can here the ABS motor engage momentarily. I usually can fix alot of things but this one is really strange!!!

Thanks again for your help,
James

[TeamExploder]

hmm....that is a bit odd...possibility that wires for the abs motor/sensor/light its possible too of a shorted wire if your abs will engage on its own...

[jvorrius]

Yes, it does really sound odd to me!

I'm going outside to reconnect the battery and try to sort this out.

This is kind of a weird way to spend a day home from work with bronchitis.

Thanks again for your help.
Once I figure this out I am going to reply back as to what i found.

James

[TeamExploder]

Yeah, it sucks having to work on your truck when ya feel like crap, good luck with it. Sorry I just don't know what else could be causing the issue.

[shorod]

When you're coming to a slow stop, is the ABS pump running or you just get the pulsation from the ABS activating? The pump runs to pressurize the system, but the pump doesn't necessarily need to run for the ABS to activate.

Have you inspected the tone rings on the axles to make sure they are in good shape? You need to inspect them closely to be sure there are no cracks causing a larger gap between two teeth than the rest, or missing pieces.

Also, the rear wheel speed sensor has been a known issue. It sounds like your focus so far has been on the front sensors. Have you taking a reading on the rear sensor and compared it against the specification?

Do you happen to have access to an oscilloscope or, even better, a scan tool with ABS software?

-Rod

[way2old]

I would also look for rust and crud in the sensors. Rod gave some good advice.. Hey Rod, I got access to them things.

[shorod]

Originally Posted by way2old

Hey Rod, I got access to them things.

Yep, and you're closer to New Jersey than I am. I guess you get to make the road trip.

-Rod