2000 Chevy Cavalier ABS and ETS issues

Brakes problem
2000 Chevy Cavalier 4 cyl Front Wheel Drive Automatic

Hi,

I am working on my wife's 2000 Chev Cavalier Z24.

She started having ABS issues.

I suspected wheel speed sensors (again) but this time the symptoms are a bit different.

When first starting the engine all of the warning light on the dash are off.

There are two symptoms of the issue.

1. Sometimes when applying the brakes the ABS seems to engage as if trying to stop on an icy road and the ABS and ETS warning lights come on.

2. Sometimes when just driving off the ABS and ETS warning lights come on without applying the brakes.

In both cases restarting the engine clears the lights.

My elcheapo DTC code reader doesn't show any faults but I don't think it is capable of reading/displaying the ABS/ETS DTC codes.

The symptoms seemed to point to wheel sensors so I checked them and they seem OK.

I have the factory service manuals for this car and the sensors were all within specs for both resistance and the AC voltage reading when spinning the wheels by hand.

Do you know if a better code reader might display some helpful information that mine isn't.

Any idea of where to look next?

Thanks in advance.

Dale.