If the vehicle registration for a commercial motor vehicle reflects a model year of 2000 or newer, but the vehicle was manufactured without an engine control module (ECM), is the carrier required to comply with the ELD rule?

Yes, a motor carrier operating a vehicle with a manufactured model year of 2000 and newer and without an ECM is subject to the ELD rule. If the currently installed engine does not support an ECM and is unable to obtain or estimate the required vehicle parameters, then the operator must use an ELD that does not rely on ECM connectivity, but nevertheless meets the accuracy requirements of the final rule. See Appendix A to Subpart B of Part 395 sections 4.2 and 4.3.1 of the ELD rule for accuracy requirements.