how to bypass the keypass III security system

The system doesn't recognize the key being used. Please understand, due to liability issues, explaining how to disable the vehicles alarm system isn't something we can do.

30 Minute Re-Learn Procedure (Domestic Vehicles Only)

Use this procedure after replacing:

The keys/lock cylinders
The theft deterrent controller module
The PCM (if necessary, see important above)

Turn ON the ignition, with the engine OFF using a Master Pass Key III Key (Black).
Observe the Security telltale, after approximately 10 minutes the telltale will turn off.
Turn OFF the ignition, and wait 5 seconds .
Repeat steps 1 through 3 two more times for a total of 3 cycles or 30 minutes .

IMPORTANT: The vehicle learns the key information and/or passwords on the ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.

Start the vehicle (the vehicle has now learned the key and password information).
With a scan tool, clear any DTCs.