Prius (2010-2015)

1. 1

   Primary
   NO service plug or cut loop on this car. OEM gives TWO disable procedures; BOTH finish by disconnecting the 12 V auxiliary battery. PROCEDURE #1 (preferred): (1) Confirm the READY indicator. If READY is on, the car is on and operational. (2) Push the POWER button ONCE to shut off. (3) If the instrument-cluster lights are already off, do NOT push the button (the car may start). (4) If the Smart Key is accessible, keep it at least 16 ft (5 m) from the vehicle to prevent restart. (5) Disconnect the 12 V auxiliary battery (under the cover in the cargo area). PROCEDURE #2 (alternate, if the POWER button is inaccessible): (1) Open the hood, remove the fuse-box cover. (2) Remove the IGCT fuse (30A GREEN) and the AM2 fuse (7.5A ORANGE) from the engine-compartment fuse box; if you can't identify them, pull ALL fuses in the box. (3) Disconnect the 12 V auxiliary battery in the cargo area.

   POWER button on dash (READY indicator in instrument cluster). IGCT (30A green) + AM2 (7.5A orange) fuses in the engine-compartment fuse box. 12 V battery in the cargo area, passenger side, in the rear quarter-panel well under a fabric cover (OEM).

2. 2

   Backup
   Procedure

Note
OEM WARNING (verbatim): "The high voltage system may remain powered for up to 10 minutes after the vehicle is shut off or disabled." WAIT 10 MINUTES before touching/cutting any orange HV cable or HV component. "avoid touching, cutting, or breaching any orange high voltage power cable or high voltage component." OEM WARNING (verbatim): "The SRS may remain powered for up to 90 seconds after the vehicle is shut off or disabled." Avoid breaching any SRS component for at least 90 s after disable. OEM: NEVER breach or remove the HV battery pack cover under ANY circumstance, including fire — risk of severe burns, shock, or electrocution. If NEITHER procedure can be performed, OEM says proceed with caution — there is NO assurance the HV system, SRS, fuel pump, or remote A/C are disabled. Treat as fully live.

12V location: Cargo area, passenger side, in the rear quarter-panel well, concealed by a fabric cover (OEM). Sealed lead-acid 12 V, negative grounded to chassis. Access via center deck board / center auxiliary box / battery cover.

Powers the vehicle control modules, gauges, audio, lights, SRS, accessories, and the electronic gearshift/P system. Disconnecting the 12 V negative is the final step of BOTH OEM disable procedures. The HV cables are switched by 12 V normally-open relays that open (stop HV flow from the pack) when the vehicle is shut off.

SRS discharge: wait 90s after airbag deployment before touching SRS components.

Pack location: Cargo area, rigidly mounted to the floor-pan cross member BEHIND THE REAR SEAT; sealed metal case, concealed by carpet in the cabin (OEM).

Pack chemistry: Nickel-metal hydride (NiMH), sealed; 28 non-spillable modules x 7.2 V. Electrolyte is a caustic ALKALINE mixture of potassium + sodium hydroxide, pH 13.5 (OEM). Pack ~90 lbs (41 kg). Not lithium-ion.

HV cable color:Orange (OEM). Positive and negative orange HV cables run from the pack UNDER THE FLOOR PAN to the front inverter/converter.

Do not cut:

• Orange high-voltage cables (entire under-floor-pan routing from the rear pack to the front inverter/converter) and all HV components
• HV battery pack (cargo area, floor-pan cross member behind the rear seat) and its metal case; never breach or remove the pack cover under any circumstance, including fire (OEM)
• SRS components (dual-stage frontal airbags, front seat-mounted side airbags, side curtain airbags, front seat-belt pretensioners, driver knee airbag); SRS may stay powered up to 90 s after disable
• Side curtain airbag deployment zone along the driver/passenger side windows (roof rails / pillar area); total roof removal NOT recommended when curtain airbags are undeployed (OEM)
• Optional roof solar panel energized output wire (up to 27 V; higher arc potential than 12 V); disable it before cutting the headliner area
• Exhaust system and fuel system (do not place cribbing or lift bags under these or the HV cables)

Reinforcement (UHSS):

• A-pillars
• B-pillars
• C-pillars / roof rails (side curtain airbag area)

Pack piercing risk: Sealed ~90 lb NiMH pack in a metal case on the cargo-area floor cross member behind the rear seat. OEM: electrolyte is absorbed in the cell plates and "will not normally leak, even in a collision"; only a catastrophic crash breaching BOTH the metal case AND a module would spill it. The caustic alkaline electrolyte (pH 13.5) damages tissue. The orange HV cables run under the floor pan front-to-rear, so any underbody tool can breach them. NiMH does not thermal-runaway like Li-ion, but a damaged pack is still ~201.6 V DC.

Live from NHTSA. Cross-check the VIN against nhtsa.gov/recalls before work.

OEM (extrication): crib at FOUR points directly under the front and rear pillars. Do NOT place cribbing or rescue lift air bags under the high-voltage power cables, the exhaust system, or the fuel system. (Secondary/common sense, not an OEM lift-point spec: avoid jacking against or piercing the cargo-area floor pan behind the rear seat (HV pack) or the under-floor orange HV cable routing.)

Coolant: No HV-pack liquid coolant documented in this OEM ERG (NiMH air-cooled).

Electrolyte color: Caustic ALKALINE mixture of potassium + sodium hydroxide, pH 13.5 (OEM); absorbed in the cell plates, small quantity, normally non-spillable. Neutralize spills with a dilute BORIC ACID solution or vinegar (OEM). Skin/exposure - remove clothing, rinse affected area with water 20 minutes, transport to medical care (OEM).

If burning, toxic vapors:

• Caustic alkaline electrolyte mist (potassium/sodium hydroxide, pH 13.5), tissue-damaging; wear PPE / SCBA (OEM)
• Smoke / combustion products from burning NiMH modules; OEM: no toxic gases under non-fire conditions, but use SCBA in a fire

Toyota Prius Emergency Response Guide (PDF) →

Last verified 2026-05-31

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