Drive Motor Control Module
WARNING: This page is about a different car, the 2023 GMC Hummer EV. However, it is still accessible from the selected car via links, so may be relevant.
The DMCM receives the BCM Prerelease Allowed signal and simultaneously the DMCM sends a challenge to the BCM via the serial data circuit upon seeing the vehicle transition from OFF to any other power mode. Both the DMCM and BCM perform a calculation on this challenge. If the calculated response from the BCM equals the calculation performed by the DMCM, vehicle operation will be allowed by the DMCM.