My 05 Impala cranks but won't start security light flashes
Just to add, passlock usually is fuel injector disable, only. There are trouble codes for the security system, manufacturer specific codes. A common issue, the wires get loose at the passlock sensor. The sensor surrounds the key tumbler. There is a 30 minute relearn procedure, probably won't work if there is an unfixed problem. Ed probably knows more about this issue than I. Just trying to help. Everybody have a good day.