Chevrolet Impala security system issue requiring key code reset after starting problems on Chevrolet Impala

Some Chevrolet Impala owners report experiencing starting problems due to security system issues that necessitate a key code reset. These issues may stem from various security systems, including Vehicle Anti-Theft System (VATS), Passkey, or Passlock. To address these problems, some owners have found success by turning the ignition key to the 'on' position and waiting for approximately 10 minutes until the security light stops flashing. Others report that disconnecting the battery for a few minutes can help reset the system. If these methods fail, some owners need to relearn the keys by inserting the master key into the ignition, waiting for the SECURITY light to turn off, and repeating this process for additional keys. In certain cases, leaving the ignition on without starting the vehicle for 30 minutes before attempting to start it again may also be necessary.