ABS light comes on but no codes

I have a friend with a 99 Regal LS that had the ABS light on full time, I scanned it with a Snap-on Modus scanner found 3 codes all for RF sensor. Once I checked it out I found the connector torn right off so a new hub was installed,and codes were cleared, as soon as the the car was started the ABS light was off but when driven a couple feet it was back on, I then scanned it again and there are no codes present. If the car sits with the ignition off for a long period (overnight) once started the light is off but when moved it comes on. I had the scanner connected and drove the car and it shows that all the wheel sensors are working and pretty much the same except at the initial point of movement they are jumbled but once rolling they match up . Does anyone know why this light is still coming on ?

Is the Snap On Modus scanner fully ABS capable to include pulling GM/Bosch ABS codes?

Since the ABS light is turning on while moving it is failing the second part of ABS initialization. Do you ever get a TRAC OFF light?

I would think it would be able to, but I'm not 100% certain. Yes the TRAC OFf light is on , as well as another one , I think its SERVICE VEHICLE.

The Snap-On Modis scan tool should if it has the right software package. For sure version 10.4 has GM ABS diagnostics capability but ouch expensive stuff.

With those lights on an ABS related DTC(s) has to be stored. Does the steering feel normal? You should have the Magnasteer variable effort ratio steering and an ABS fault will cause it to act up or be stiffer than it should.

Are you sure all wheel sensors and the connections are good? Another issue with GM ABS systems is the EBTCM module if previous possibilities is verified good. It is the module located on the front of the ABS modulator/motorpack assembly where the big electrical connector is located. The EBTCM module also controls the Magnasteer.

I have a friend with a 99 Regal LS that had the ABS light on full time, I scanned it with a Snap-on Modus scanner found 3 codes all for RF sensor. Once I checked it out I found the connector torn right off so a new hub was installed,and codes were cleared, as soon as the the car was started the ABS light was off but when driven a couple feet it was back on, I then scanned it again and there are no codes present. If the car sits with the ignition off for a long period (overnight) once started the light is off but when moved it comes on. I had the scanner connected and drove the car and it shows that all the wheel sensors are working and pretty much the same except at the initial point of movement they are jumbled but once rolling they match up . Does anyone know why this light is still coming on ?

You may want to look at the wheel with the new hub.
If you never got it in the groove right it may have broken again.

Cheers
Stripe

When I first scanned it I took it for a spin and it showed no value on the RF so I knew something was wrong , once I replaced the hub with sensor now it shows the same value as the other 3 when rolling so I would think it is in properly.

BNaylor , the steering does seem fine , doesn't seem stiff , feels normal.