How do you reset the ecm on a freightliner Columbia?

To reset the ECM (Engine Control Module) on a Freightliner Columbia, you can start by disconnecting the negative battery cable and leaving it disconnected for about 15 minutes. This will allow the ECM to reset. After reconnecting the cable, turn the ignition to the "ON" position without starting the engine for a few seconds, and then start the vehicle. This process clears any temporary codes and resets the system.