My 1997 Monte Carlo has developed an odd problem.
My ABS gently activates in the final 10 or 20 feet of a stop. It is definitely the ABS. Interestingly, the ABS light does not illuminate.
I checked all of the components, and discovered the passenger frint reluctor or tone ring is broken: I was able to turn it by hand on the axle. There was no other discernable damage.
Pulling the ABS fuse cures the problem...and disables the ABS completely.
I considered having the ring replaced, and it is very expensive...so, I glued the ring together, assuring that it could no longer spin freely on the hub (it really didn't spin easily, but the epoxy assures it cannot spin).
This made no change in the problem.
I'm a former master mech, but have been away from the practice for a very long time. My knowledge on this topic is minimal.
I will take a guess: the problem appears to be one of signal strength, rather than the damaged reluctor (as it appears to have the same gap and position as the others--but, I don't discount the possibility that the reluctor is the culprit).
Because the signal (voltage) from the reluctor/tone wheel decreases as the wheel speed decreases, I believe that maybe there is increased electrical resistance somewhere in the system, which is dropping overall voltage.
Therefore, the voltage from one of the sensors is being read by the computer as lower than normal, but not low enough to pulse the ABS continuously. Yet, as speed approaches zero, the voltage drops faster than it should, thereby pulsing the ABS.
The increased resistance could be:
Increased gap between the tone ring and sensor
Bad sensor (but, it seems that the sensor would either work correctly or not...I'm just guessing!)
Any connections along the circuit to the computer.
Heck, I'm not even sure which wheel is causing the problem.
So, I guess the easiest thing to do is to check the air gaps, then check and clean all connectors. Next would be individual sensor tests: I would guess there are published values for voltage output, but where to find the info? I could check all of the sensors and see if there is one reads redically different from the others.
I could be full of [censored]...but if anyone can help, I sure can use it!
My ABS gently activates in the final 10 or 20 feet of a stop. It is definitely the ABS. Interestingly, the ABS light does not illuminate.
I checked all of the components, and discovered the passenger frint reluctor or tone ring is broken: I was able to turn it by hand on the axle. There was no other discernable damage.
Pulling the ABS fuse cures the problem...and disables the ABS completely.
I considered having the ring replaced, and it is very expensive...so, I glued the ring together, assuring that it could no longer spin freely on the hub (it really didn't spin easily, but the epoxy assures it cannot spin).
This made no change in the problem.
I'm a former master mech, but have been away from the practice for a very long time. My knowledge on this topic is minimal.
I will take a guess: the problem appears to be one of signal strength, rather than the damaged reluctor (as it appears to have the same gap and position as the others--but, I don't discount the possibility that the reluctor is the culprit).
Because the signal (voltage) from the reluctor/tone wheel decreases as the wheel speed decreases, I believe that maybe there is increased electrical resistance somewhere in the system, which is dropping overall voltage.
Therefore, the voltage from one of the sensors is being read by the computer as lower than normal, but not low enough to pulse the ABS continuously. Yet, as speed approaches zero, the voltage drops faster than it should, thereby pulsing the ABS.
The increased resistance could be:
Increased gap between the tone ring and sensor
Bad sensor (but, it seems that the sensor would either work correctly or not...I'm just guessing!)
Any connections along the circuit to the computer.
Heck, I'm not even sure which wheel is causing the problem.
So, I guess the easiest thing to do is to check the air gaps, then check and clean all connectors. Next would be individual sensor tests: I would guess there are published values for voltage output, but where to find the info? I could check all of the sensors and see if there is one reads redically different from the others.
I could be full of [censored]...but if anyone can help, I sure can use it!
Last edited: