7578-2. Steps to take in an emergency 
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
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When trouble arises
Once the hybrid system has started, remove the jumper cables in 
the exact reverse order from which they were connected. 
To install the engine cover, conduct the removal procedure in 
reverse. After installing, check that the fixed pins are inserted 
securely. 
Once the hybrid system starts, have the vehicle inspected at any 
authorized Toyota retailer or Toyota authorized repairer, or any reliable 
repairer as soon as possible.
■ When opening the cover of the positive (+) battery terminal 
 P. 645 
■ Starting the hybrid system when the 12-volt battery is discharged 
The hybrid system cannot be started by push-starting. 
■ To prevent 12-volt battery discharge 
● Turn off the headlights and the audio system while the hybrid system is off. 
● Turn off any unnecessary electrical components when the vehicle is running 
at a low speed for an extended period, such as in heavy traffic. 
■ When the 12-volt battery is removed or discharged 
● Information stored in the ECU is cleared. When the 12-volt battery is 
depleted, have the vehicle inspected at any authorized Toyota retailer or 
Toyota authorized repairer, or any reliable repairer. 
● Some systems may require initialization. (P. 792) 
■ When removing the 12-volt battery terminals 
When the 12-volt battery terminals are removed, the information stored in the 
ECU is cleared. Before removing the 12-volt battery terminals, contact any 
authorized Toyota retailer or Toyota authorized repairer, or any reliable
repairer. 
■ Charging the 12-volt battery 
The electricity stored in the 12-volt  battery will discharge gradually even when 
the vehicle is not in use, due to natural discharge and the draining effects of 
certain electrical appliances. If the vehicle is left for a long time, the 12-volt
battery may discharge, and the hybrid system may be unable to start. (The 
12-volt battery recharges automatically while the hybrid system is operating.)
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