How do you replace the CEM on a 2000 S80 Volvo?

To replace the Central Electronic Module (CEM) on a 2000 Volvo S80, first disconnect the negative battery terminal to ensure safety. Then, remove the trim panel under the dashboard on the driver's side to access the CEM, which is located behind it. Disconnect the wiring harnesses from the CEM and unbolt it from its mounting. Install the new CEM by reversing these steps, ensuring all connections are secure before reconnecting the battery.