Toyota 2004 Highlander Owner's Manual page 204

Audio remote controls (steering switches)
180
'04 HIGHLANDER_U (L/O 0308)
Some parts of the audio system can be
adjusted using the switches on the steer-
ing wheel.
Details of the specific switches, controls,
and features are described below.
−" switch
1. "+
2. " " switch
3. "MODE" switch
2004 HIGHLANDER from Aug. '03 Prod. (OM48478U)