Disconnect both battery cables and wait 5 minutes then reconnect - first then + and when your alarm sounds press the disarm button otherwise your alarm will go into theft mode and it will not start at all after this has been done the car will idle a little rough that's normal it has to relearn the computer values programmed in after about 5 minutes take the car for a ride for about 20 miles so it can continue to relearn the computer settings and if you did it right no more trouble code if not search again for code and if same one comes up check and clean the connector and inspect the wires for burns or breaks