This SAE Recommended Practice establishes guidelines for the operation of automotive keyless ignition systems with the goal of helping to minimize user instigated errors. For the purpose of this Recommended Practice, user instigated errors may include: ? the inability to start and stop the vehicle propulsion system, ? exiting the vehicle with the automatic transmission in a non-parking gear, ? exiting the vehicle while the vehicle propulsion system is enabled, ? exiting the vehicle while the vehicle propulsion system is disabled, but the accessory or electrical systems are active. To help minimize these errors, this Recommended Practice contains design recommendations pertaining to uniform labeling, operating logic, indication of vehicle ignition/control status, and physical control characteristics of keyless ignition systems. This Recommended Practice applies to keyless ignition controls permanently mounted in passenger cars, MPVs, and trucks 10 000 GVWR and under. It does not apply to remote start/remote stop systems that provide remote controls to start or stop a vehicle engine from outside the vehicle.