Toyota 2014 Prius Owner's Manual page 548

5-2. Steps to take in an emergency
■
The interior lights and headlights do not turn on, or the horn
does not sound
One of the following may be the cause of the problem:
● One or both of the 12-volt battery terminals may be discon-
nected.
● The 12-volt battery may be discharged. (→P. 550)
Contact your Toyota dealer if the problem cannot be repaired, or if
repair procedures are unknown.
Emergency start function
When the hybrid system does not start, the following steps can be
used as an interim measure to start the hybrid system if the
"POWER" switch is functioning normally:
Set the parking brake.
STEP 1
Turn the "POWER" switch to ACCESSORY mode.
STEP 2
Press and hold the "POWER" switch for about 15 seconds
STEP 3
while depressing the brake pedal firmly.
Even if the hybrid system can be started using the above steps, the
system may be malfunctioning. Have the vehicle inspected by your
Toyota dealer.
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