Gretio Common Terms & Glossary

ABS Module – Has been replaced by the EBCM. Modern ABS systems are highly integrated into traction control systems.

Air Bag Module – Refers to actual air bag component. These are non serviceable and must be replaced. Diagnostics are done through a separate module known as the SDM or IRSDM.

BCM – Body Control Module

Control Function – Some command you give to a control module which the control module then full-fills. This could be anything from increasing idle speed to programming certain information.

CAN – Controller Area Network. Network Standard which all automotive computers have used since early 2000s.

CAN-FD – Faster CAN which is incompatible with prior standards. Set to gradually replace CAN after 2022.

CCM – Chasis control module

Control Module – Most computers on a vehicle will be network addressable and will generally be referred to as control modules. In short. It just means it’s a computer.

DoIP – Diagnostic over IP. Newer diagnostic architecture which uses TCP sockets instead of OBD2 ports.

DPF – Diesel particulate filter. An emissions component present on all vehicles manufactured after 2007.

ECM – Engine Control Module

EBCM – Electronic Brake Control Module

HPCM – Hybrid Powertrain Control Module, also used for EV (non hybrid).

ICCM – Instrument Cluster Control Module. Many times referred to as the IPC (Instrument Panel Cluster).

IRSDM – Inflatable restrain sensing and detection module.

MDI – This is an interface used by gm dealerships to connect to vehicles.

NOx – Catch all for any Nitrogen bound to a number of oxygens. This is a harmful exhaust product and is produced by both gas engines and diesel engines.

OBD2 – A standardized port required by law to be present on all vehicles (electric, gas, diesel, etc…).

PID – Parameter ID. Data you can view from a control module.

SCR – Selective Catalytic Reduction. A second emissions component introduced around 2010. Uses ammonia (from a Urea solution) to reduced nitrogen oxides (NOx ie NO, NO2, etc…) to less harmful components already found in the atmosphere (N2, and Water).


SDGM – Serial data gateway control module. This was introduced to help isolate some key modules from internet facing control modules (i.e. OnStar systems, radio, bluetooth connectivity modules). Most GM models after 2017 will have a gateway module.

SIR – Supplemental inflatable restraint system. See IRSDM.

TCM – Transmission Control Module