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ABS Not Working

Big T

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Fullerton, CA
After replacing the front bearings last fall, the ABS was working nicely. That is until the wires on the Left Front sensor rubbed through. I tried splicing them and only periodically did the ABS work. I ordered a new AC Delco Sensor from RA and it took a few months to get around to putting it in. I sense that there was pent up fear from the bearing replacement job where the bearing hub bolts were darn near impossible to get out. Not this time. I had the hub off in minutes, replaced the sensor and reinstalled. Unfortunately, the ABS light is still on. I checked the ABS fuse in the engine compartment and that's fine. As recently as a couple weeks ago the ABS was working sporadically with the spliced sensor in place (hard to get a good splice on it).

What am I missing? Should I be checking for frayed sensor wire on the right side? Is there any test that I can do?
 
The only test I know of is to use an ohm meter, not sure of what reading depicts a bad sensor.
 
Seems to me that once you throw the code the ABS light will be on until the code is cleared. I wasn't able to clear my code (ABS Light) with my EFI LIve scanner, nor could Advance Auto do it. It will have to be someone with a Tech II to clear it. While you're at it have it scanned to see if there are any outstanding codes not addressed with the sensor replacement. IF the other sensor is bad it will come up on the Tech II.

OnEdit: I just remembered I was able to clear the ABS Light by starting the truck, turning it off, then repeat twice. Don't move the truck or apply the brakes while doing this. It's a long shot, but it's cheap....good luck.
 
Last edited:
Seems to me that once you throw the code the ABS light will be on until the code is cleared. I wasn't able to clear my code (ABS Light) with my EFI LIve scanner, nor could Advance Auto do it. It will have to be someone with a Tech II to clear it. While you're at it have it scanned to see if there are any outstanding codes not addressed with the sensor replacement. IF the other sensor is bad it will come up on the Tech II.

OnEdit: I just remembered I was able to clear the ABS Light by starting the truck, turning it off, then repeat twice. Don't move the truck or apply the brakes while doing this. It's a long shot, but it's cheap....good luck.

The ABS was disconnected when I bought the truck. When I connected it, the ABS light came on. ABS was definitely not working. Then I rebuilt much of the front end, including new CV shaft and bearing hubs with new sensors. Hooked the ABS back up and it worked like a charm, that is until I frayed through the left front wire to the sensor. I figured replacing that would solve the problem.

I'll go try disconnecting it to see if the light goes out. Then reconnect it. Maybe the RF sensor is messed up?

I disconnected the small plug on the left side of the ABS pump. Nothing. I disconnected the larger plug on the front of the ABS pump and the light goes out. Plug it back in and the light comes back on. Visually checked the RF sensor wire and there are no frays.

Sounds like I'll have to take it in to have it scanned.
 
The ABS was disconnected when I bought the truck. When I connected it, the ABS light came on. ABS was definitely not working. Then I rebuilt much of the front end, including new CV shaft and bearing hubs with new sensors. Hooked the ABS back up and it worked like a charm, that is until I frayed through the left front wire to the sensor. I figured replacing that would solve the problem.

I'll go try disconnecting it to see if the light goes out. Then reconnect it. Maybe the RF sensor is messed up?

I disconnected the small plug on the left side of the ABS pump. Nothing. I disconnected the larger plug on the front of the ABS pump and the light goes out. Plug it back in and the light comes back on. Visually checked the RF sensor wire and there are no frays.

Sounds like I'll have to take it in to have it scanned.
When the wires rubbed through on the speed sensor it probably threw another code. Try starting it two or three times in a row, start it, shut it down, repeat twice and see if the light goes out, if not then get it scanned...it cost me $98 to get it scanned so try the free stuff first...also check the other speed sensor wires too.
 
Also, is the ABS working? Or, is it that just the light is on? I tested mine on a gravel road, got a little speed up and jammed on the air. You should feel the vibration in the pedal if it's workin'.
 
If it was me, I'd take it out to a big grassy area (wet with rain or dew), get some speed up and hit the hooks hard to cycle it a couple times or so. See if that does it. IIRC, that's what the techII simulates.
 
Also, is the ABS working? Or, is it that just the light is on? I tested mine on a gravel road, got a little speed up and jammed on the air. You should feel the vibration in the pedal if it's workin'.

No, the ABS is not working. It was a couple weeks ago, but intermittantly with the spliced sensor. Before the sensor wires wore through, it was working great.
 
That's a little odd. I can't think of any reason that the sensor would kill the ABS after being replaced, especially since you said that you checked the fuse and all conections. I guess it's scann time unless somebody else has some ideas.
 
OK, took the Burb offroad and on the return I noticed THE ABS LIGHT WAS OUT. So I did a couple tests and sure enough the ABS was working. Then I did one final test with the passenger wheels on dirt, driver side wheels on pavement. It worked, but then the ABS light came on again. This has to be some sort of wiring or connection problem. The trail we took is a serious offroad jeep trail. There's one spot where I had to turn around as it was impassable with the long wheel base. Gave the suspension a good workout and probably the ABS wiring. I need to give it a more thorough look see.
 
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