Hey everyone, I have a 96' 4WD 4.3L blazer that has been having ABS issues. It all started with the ABS light coming on this winter. Ran the code and it lead to the drivers side wheel speed sensor. I replaced the wheel speed sensor and while replacing it I found that the wires on the old wheel speed sensor was severed. So I thought easy fix. I then cleared the codes and no lights reappeared. Then I took it for a test, all was fine until I get going 35MPH or above. The ABS activates all of the time for no reason. The pedal will be super hard initially, then let up, then the ABS kicks in again. Some time normal braking will occur then the ABS kicks in then back out and the blazer will pull very hard to one side. I checked for codes and nothing appears.


I have searched for answers everywhere and done everything pertaining to the wheel speed sensors (cleaned, checked for crack) but still don't have a clue. I checked the voltages of both wheel speed sensors while rotating the hub by hand and both checked out normal. The part store even gave me a new wheel speed sensor to try but I ended up with the same results.


Sorry for the long first post but this is just frustrating now. Anyone have any ideas?


Thanks

 

The most accurate way is to have a scanner hooked up and drive it at that speed and see what the sensors are reading. One may be reading differently than the other. The air gaps may be different. The tone ring on the hub may be damaged ...etc

 

How do you adjust the air gap on the new sensor? It does not seem like there is any way to make an adjustment?

 

if after changing the sensor you have a "newer" problem then it's got to be the sensor or some other issue with it like clearance on the hub on the sensor?

 

How are your hubs or other suspension parts. That can cause issues also

 

Suspension and hubs all seem good. This problem only occurred after replacing the old wheel speed sensor. I don't think there is a way to adjust the air gap between the sensor and the exciter. The sensor is riveted to the splash plate. Any ideas for adjustment?

 

go to a auto parts store and have them read it. should tell you just what it is

 

Okay, hooked into a scan tool today. Only code I got was P0719 TCC/Brake Switch'B' Circuit Signal Low/Short. I also checked the wheel speed sensor readings while driving. Both the L and R gave the same reading no matter what speed or if brake was applied. They even gave the same reading when the ABS kicked in. So I would assume it has nothing to do with the wheel speed sensors at this point.