If the vehicle does not track engine hours, can the record begin with “0?”

If it is not possible to obtain the engine hours from the ECM, then the ELD may begin recording engine hours at “0” for the given engine the first time the ELD is used with that engine. After the first use, the ELD must continue to keep and use an aggregate total from the first time it was installed or used with an engine. Ideally, back office systems can share this aggregate total so that any other ELD used with the engine can start at the aggregate total, rather than “0.”