ABS goes active under normal braking conditions, any ideas?

[coinball]

A month or two ago the ABS started to come on now and then when I'd be pulling into a parking spot, or coming to a quick stop. Very gradual braking would not activate the ABS.

I don't have any ABS lights on in the dash and everything is working fine otherwise.

Both front and rear brakes have been redone this past week and while the Tahoe stops much better, the problem still exists.

Any ideas?

[Robyn]

Very likely that you have a sensor with an issue.

Get a scanner on the thing and then watch whats going on while the brakes are applied.

A front wheel sensor thats going south could definately cause this anomaly.

Best

Robyn

[coinball]

The front wheel sensors are integrated into the wheel hubs, right?

Is there a specific scanner I would have to use to view the ABS inputs? I don't think my GMTD scanner can view the ABS stuff...

[Robyn]

A tech 1 or equivalent will do it.

Robyn

[Kennedy]

Pretty common issue and easy to fix. The speed sensor is held into the hub assy with a single bolt. What happens is rust forms between the hold down tab and the hub essentially "heaving" the sensor out of the hole just far enough that in low speed maneuvering it loses signal. Pull the sensors, sand clean, smear the surface with dielectric grease and reinstall.