Detroit Diesel Electronic Controls System Figure 9. Aftertreatment Control Module The ACM controls the aftertreatment functions. When a malfunction or other problem is detected, the system selects an appropriate response to deliver to the operator. The ACM uses the inputs from the sensors to control the ATS. The data is compared to the characteristic maps stored in the ACM. Transmission Control Module Vehicles equipped with a Detroit Transmission will also be equipped with a TCM. The TCM will be mounted on the left side of the transmission (see graphic below). 36 All information subject to change without notice. Copyright © 2022 DETROIT DIESEL CORPORATION DDC-SVC-MAN-0217