abs brake lite is on.

[Thudpucker]

97 F-150/4X4/4.6/auto Its been on for a month. The code reader didn't reset it, or it came right back on after resetting. The Brakes work oK. How do I bleed that Computer? I searched for ABS lite and Brake lite on but got nothing. We probably have had 50 or so threads on that in the last two years. What aint I doin right?

[steve(ill)]

when you startup the truck it goes thru a test. if the light is out, your test passed. if you start moving and the light comes on at 5 MPH, then the sensor at one wheel is not working. is your light on at startup setting in the driveway? an engine code reader will not work on the ABS.

[dgsm24]

yea i have the exact same truck as you, and have the same problem, when i turn the truck on its not on, but 5 seconds after turning it on(not having to move it or putting it in drive) it turns on, would that be my sensor? anyone have a pic of where they are located?

[Thudpucker]

That's good info. Very subtle.
My lite comes on at start-up and stays on.

[Hybris]

My truck does the same thing but here is a twist.

We (My Father the actual onwer) have replace several sensors but not all I think.

When it rains or is otherwise wet I have ABS brakes usually.

When its dry I have traditional non-ABS brakes usually sometimes in dry weather I have ABS other times I have no ABS in the rain.

We have gotten tired of throwing money at the problem so maybe after 8+ years of dealing with it this thread might have an answer.

[steve(ill)]

when you start the motor, the trucks computer goes thru a test. if the light is no before you move the truck, you failed the test. you must be moving to see if the sensors are reading. the failed test can be a sensor that is not connected , or it could be the ABS module, etc.. Only if the light comes on after moving do you know the sensor is not reading correcly, but is connected since it pasted the initial continuity test.

[Thudpucker]

I replaced that inductor/sensor on top the Differential a year or so ago. The Plastic connector broke and I had to Tie-strap it together.
I dont think I've ever felt the computer actuating the pedal when I try to skid on gravel.
I'm wondering now, if I ever had good ABS braking?

IS there any bleed valve on that ABS computer?

[blue2golf]

I had to replace the speed sensor on top of my rear diff. a couple of years ago after the ABS light came on. I replaced the sensor, then disconnected my battery for a few minutes to clear the codes and I haven't had a problem since.

[SMok]

Check the resistance of the sensor on the rear diff. It should be aprox. 1200-1800 ohms. If not, replace it. This is the problem most of the time. More then likely you will have an open sensor (no resistance at all)

[Thudpucker]

I checked yesterday.
My ABS light only comes on occasionally during operation. Otherwise it comes on for the test and goes off.

It's my "BRAKE" lite that's on all the time. As if my Handbrake is on or ect.

What does that mean to me?

[SMok]

is your brake fluid low?

[kabcpapc]

Just had that problem on my 1997 F150 XLT. My son crawled under the truck and I told him to find the wiring going to the sensor. It looked ok but when he unwrapped the tape he found the wires were severed. Stripped the insulation and joined them together and the ABS light went off. Go figure!

[fordman49]

Kabcpapc, Hey man what senser did you look for, my brother had a 98 f-150 with a 4.2L and he has that same problem. We have swaped the main brake unit and the senser that is on the rear end but it didn't work. I looked in several different manuals for info on the ABS system but really didn't find any answers. The only thing that we haven't changed is the ABS module I don't even know where it is located? But if anyone has any info on that I would be truely thankfull. Help please

Thanks
Hector, Yorktown, TX

[Thudpucker]

My brake fluid is still up in the upper half of the resivour.

That frayed wire might have been cause by somebody removing the tail cone to replace the speedometer drive gears. I had to do that, But a put a male/female push connector on my wire.