Central Electronic Module (CEM) (2001-2004): Design: Horn
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2009 Volvo S60, 2008 Volvo S60, 2007 Volvo S60, 2006 Volvo S60, and 2005 Volvo S60. However, it is still accessible from the selected car via links, so may be relevant.
There are two horns in front of the radiator. There are four switches in the steering wheel. The horn is activated when one of these is closed.
The signal continues for as long as the switch is closed.
The horn is also activated when the panic alarm button on the remote control is pressed (certain markets).
The power supply to the horns is via a relay in the relay box in the engine compartment.
There are diagnostics for the relay for the horn.