Central Electronic Module (CEM) (2003-2004): Design: Horn
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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.