ABS pulsates when braking at speeds over 45

carriesguy

I have a 2000 Bonneville that when driving over 45 and braking the ABS pulses until the speed drops to 45 then stops. The problem started right after I had a tire go flat and replaced. The tire pressure light came on when the new tire was installed. I reset the warning light and it has not come back on. Shortly after the ABS pulsing started. I replaced the rotors pads and calipers on the front but the problem is still there.

imidazol97

Is the tire the same brand and size as the others? IS THE PRESSURE SET THE SAME?

When braking does the ABS indicator light come on showing it's intentially cycling one or more of the wheels?

Is the sound the Brrrrrr sound of the brakes pulsing ( I know it probably is, but I had to ask!)?

When you reset the tire pressure system, did you do it while the car was rolling? Had the car been sitting in the sun so one wheel was very hot and higher in pressure and the other was cool? Then when you're driving later, the system senses a difference in rotational speed?

I know of a new Buick where the dealer replaced a defective tire with a different width tire, e.g., 205 with 195 or 215. That would occasionally give a brake system light when they turning into the downhill driveway and the weight shifted to the front tires.

carriesguy

Same size not brand. Pressures all same. Reset while setting still. No sun. Drove 30 min. prior to cheching pressures and reseting.

imidazol97

Next step for me would be take out the fuse for the ABS system. Then drive the car a few days and see what behavior your get.

If behavior had disappeared then reinsert fuse and have checked to see which input sensor is giving wrong impulse.

carriesguy

OK Did The Fuse. Never did get a error code tho. Will drive then report findings.

carriesguy

ok put the fuse back in problem came back. Going to try bleeding the abs pump.

imidazol97

I believe the Tech II or a few other units that are similar can actually cycle on the ABS pump as a way of bleeding it.