How To Perform a Drive Cycle From Cold Start
Great question! A cold-start simply means allowing the engine to cool down enough for it's coolant temperature to return to as close to ambient air temperature as possible, and on certain model vehicles, allow for the EVAP system to complete its self-test/monitor. The key does not need to be in the ignition during this cool down period. It is only required that the ignition be in off position and for at least for one hour. In unusually cool weather conditions it is especially important to follow the one hour ignition off requirement as engine temperatures may lower significantly faster.
How Long Do I Have To Wait To Perform the Drive Cycle Again?
Also if an engine has previously been started, has run for at least 5 minutes and then turned off, you must again turn off the engine with ignition off for at least an hour. So in essence a cold-start is two fold. It requires the engine temperature to return to cold, but more importantly needs the ignition to be in off position. If your particular vehicle's drive cycle has a key in the ignition but engine off requirement during any part of the driving pattern, it'll be indicated in detail. For the majority of vehicle drive cycles, cold-starts do not require the key in the ignition until actually ready to begin the drive cycle.
posted by SmogTips Support
