Without Scan Tool
DTC CHECKa. Present DTC check
First, make sure that the headlamps and the ignition switch are OFF. Then turn the ignition switch ON and OFF repeatedly 3 times within 15 seconds while pressing either the PLAY or VOLUME + button. This allows the system to enter current diagnosis mode. Refer to the DTC chart for details.
b. Past DTC check
First, cover the automatic light control sensor with an opaque cloth. Then, turn the headlamp switch ON and OFF repeatedly 3 times within 15 seconds while pressing either PLAY or VOLUME + button and check that the LED on the telephone switch (Mayday switch) dims in response to the headlamps' lighting. This allows the system to enter past diagnosis mode.