sheriffav8r

I just got the dreaded ABS/Brake light on. Resets when I stop and turn off the vehicle. I think the speedo is working fine and the cruise works fine. I'm going to replace the RWAL speed sensor on Monday, but am planning a 1000 mile trip before that. Is it just that the ABS is inop or is there something happening that may be permanent if I keep driving this? I haven't done anything recently to my drivetrain. All fuses are okay.

So my course of action should be: Replace the speed sensor and check the tone ring while I have the sensor out. Check for a vacuum leak. Check that the brake lights and speedo work properly.

Anything else?

CTDTANK

Take the Jet!

93-331-29psi

The brakes will work fine with the ABS light on, however there will most likely be no ABS feature. Probably a bad sensor at one of the wheels.

VADSLRAM

Just realize that the rear wheels will lockup now....like they always would, and give a few more feet between you and the next guy. Mine has been on since it started getting cold and even after I replaced the sensor. I'm waiting until spring to run the wires. My guess is a corroded wire between sensor and brain.
My fog lights died two yrs ago and it turned out that in the middle of the wire it rotted out.

infidel

I read about folks here putting electrical tape over the lights because they've been on so long so guess it's ok
I personally would fix it ASAP but at the same time if I had a trip planned and didn't have time then I wouldn't worry about it.
Your truck has hydro assist brakes, vacuum leaks would have nothing to do with the lights.

sheriffav8r

Thanks for the info. The dealer says I only have RWAL and not 4W ABS. Is this true for the 2001.5s with 4 wheel discs? Also, are there any other possible causes for the lights other than described above? I don't mind shelling out $38 for a new speed sensor but just want to make sure I've covered all my easy bases....

atc250r

If the light is really bothering you just pull the "ABS Light" relay from the underhood fusebox. I never had any good experience with the ABS in my truck. It is a primitive (3 channel) system that was marginal at best when it was new. Mine stopped working and I'm glad it did.

John

Silver R/T

if you got too much snow inside wheels it might short out your sensor and your brake/ABS light will come on. Try blowing out any moisture, etc .

wadecool

Its probably the abs sensor on the rear diff. I took the sensor off & cleaned it and it fixed the issue. Also, I drove mine for a while with the abs light on before fixing it, so you should be ok.

nickg

Before replacing the sensor, check the wiring between the sensor and the frame, it usually breaks right where the sensor wire goes into the main harness, remove the loom and run your thumb nail against the wire, if it's broke internally you will feel it, remember to tug & pull against the wire, this is one of thoes times you MUSt touch as looking at it and thinking its looks good is the wrong way to go

sheriffav8r

Replaced the RWAL sensor over the diff. It practically came out in pieces so I think it was time to replace it. The lights stayed on so I broke out the service manual and troubleshot the 4 wheel ABS system. The rear wheel lines go to the top of the CAB next to the engine bay fuse center. They are the lines to the far right on the large connector. If you have 4 wheel ABS there is another separate connector to the right of the main one on the CAB. The rear sensor reads 1800 ohms if it's good. I tested the lines for the left and right front sensors. The left front showed open so I bought another line for it. They should test at about 1100 ohms if they are good. I pulled the tire off and removed the two bolts holding the whole caliper on then could pull the rotor and caliper off as a unit (supporting it and not letting it hang down). Replacing the ABS sensor this way was fairly painless after I figured out how to do it. The rear sensor is $38 and the front is $81. Both the front left and right are identical parts. Lights are now out and ABS works fine.

Note to self: remove McGard key lugnut from nut before replacing hubcap.

I drove 700 miles on a trip thinking I bent the heatshied tab up too far and it was rubbing on the inside of the rotor. I felt like a grade "A" dumba$$ when I pulled the hubcap off to fix the problem....