The service active handling display has been on for a few months now on my 02 c5.
The brake pedal occasionally vibrates when applied, and the car pulls to one side
when the pedal vibrates. I have been disabling the active handling with the
button on the console which stops the brake pedal vibration.
Today I started checking for bad grounds. I disassembled the two connectors
by the headlights, two connectors inside the drivers side kick panel and one connector
inside the passenger side kick panel. All connectors showed no signs of corrosion.
I cleaned them up anyway and reassembled them.
Took the car for a test and "active handling" would randomly flash on the display
for a few seconds and go off. Occasional brake pedal vibration was still there but not as
severe.
Checked under hood again and found negative cable to battery was a little loose.
tighted it up and went for another test. This time the service active handling soon AND
service engine soon display came on. Active handling icon on the dash also lit up.
This is driving me crazy. Can anybody help??

 

I have an 04 C5 which I haven't owned for long. I had the same thing occur. The lights flashed 'service active handling' and I noticed erratic behaviour (the best was what felt like the wheels be braked at 70mph - pretty scary). Anyway I disabled it and the traction control, just as the rain sets in, until I could get it to a chevy dealer. Luckily it was covered under warranty but they ended up replacing a wheel speed sensor.

They scanned a code of 28114. Then this followed by C1287 steering wheel position sensor with undocumented code 87S1. Performed something per Document #849965 and passed test. Road ran it and a duplicate occured. They then checked C102 for corrosion and replace steering sensor. They then road ran it without problem so it looks like this fixed it.

Kind of criptic but I hope this helps.