ABS problem but no light

[metalmechanic]

sort of a weird problem here. during normal braking, such as coming up to a stop sign, something happens at the last shift (2nd to 1st). The brake pedal vibrates really bad, much worse than with a warped rotor. this last maybe 1/2 a second, and then there is a strange vibration in the steering wheel itself, like a sensor of some kind being tripped. This only happens sometimes, and if I let off the pedal at the right time then it won't happen at all.

Now, I pulled the in dash fuse for the ABS, and the problem went away. Put the fuse back, and the problem comes back. So it is an ABS problem. But no ABS light comes on. The light works because it comes on and goes off when I start my truck, just like it should.

Anyone have any ideas?

I have tried to search, but can't find anything similar!

 

[96eb96]

flaky sensor

sort of a weird problem here. during normal braking, such as coming up to a stop sign, something happens at the last shift (2nd to 1st). The brake pedal vibrates really bad, much worse than with a warped rotor. this last maybe 1/2 a second, and then there is a strange vibration in the steering wheel itself, like a sensor of some kind being tripped. This only happens sometimes, and if I let off the pedal at the right time then it won't happen at all.

Now, I pulled the in dash fuse for the ABS, and the problem went away. Put the fuse back, and the problem comes back. So it is an ABS problem. But no ABS light comes on. The light works because it comes on and goes off when I start my truck, just like it should.

Anyone have any ideas?

I have tried to search, but can't find anything similar!

one of your wheel sensors is reporting erroneous information to the ABS computer. I had a problem like that on a thunderbird. You won't get a light, because the computer "thinks" there is something slippery under the wheel and actuates abs. Those sensors exposed to all the elements eventually develop intermittent issues. The other unlikely thing is a bad tone ring on the wheel hub.

This is what you can do.. Unplug each front ABS sensor, connect a ohmmeter at the end of the cable and wiggle the wire from end to end. When you see a flaky reading you know what has to be replaced. Another thing is to see which wheel (or both rears) is acting up when you stop. A friend can help with this.

 

[metalmechanic]

Thanks!

Anyone happen to know the ball park spec for a correct reading on an ABS sensor?

 

[96eb96]

Thanks!

Anyone happen to know the ball park spec for a correct reading on an ABS sensor?

Its a few ohms, and you can probably find it by comparing both sides. They also produce an A/C voltage when you spin the wheel. Maybe disconnect the sensor and run a wire into the cab and watch the meter as you stop(of course not on a busy street!).

You are looking for an intermittent fault or sudden changes in value. If the sensor was always bad you would have a light or problems at other times.

 

[metalmechanic]

I'll give it a try next time i'm at work. Just in case, is there anyway to shut off the ABS light on the dash, short of fixing the problem?