Can Check
Basically - the stereo isn't able to communicate with the cars system
In a 2002 - i thought they were NON canbus'd radio's
it started in around 2003 ish iirc
Anyway
You need to pop the stereo out - have a look behind to see if the wiring plug power side has 2 thin wires pink/black and pin and white iirc on that tooo
If not - then that stereo will never work in that car