If the battery is discharged
The following procedures may be used to start the engine if the vehicle’s battery is discharged.
You can call your Toyota dealer or qualified repair shop.
If you have a set of jumper (or booster) cables and a second vehicle with a 12-volt battery, you can jump start your vehicle by following the steps below.

- Vehicles with an alarm system: Confirm that the electronic key is being carried.
When connecting the jumper (or booster cables, depending on the situation, the alarm may activate and doors locked.

- Open the hood.
- Remove the engine cover.
Lift the edge of the cover to fixed pins, and then pull the cover towards you to remove.
- Connect the jumper cables according to the following procedures:

- Connect a positive jumper cable clamp to the positive (+) battery terminal on your vehicle
- Connect the clamp on the other end of the positive cable to the positive (+) battery terminal on the second vehicle
- Connect a negative cable clamp to the negative (-) battery terminal on the second vehicle
- Connect the clamp at the other end of the negative cable to a solid, stationary, unpainted metallic point away from the battery and any moving parts, as shown in the illustration.
- Start the engine of the second vehicle. Increase the engine speed slightly and maintain at that level for approximately 5 minutes to recharge the battery of your vehicle.
- Vehicles with a smart key system only: Open and close any of the doors of your vehicle with the engine switch off.
- Maintain the engine speed of the second vehicle and start the engine of your vehicle by turning the engine switch to the “ON” position (vehicles without a smart key system) or turning the engine switch to IGNITION ON mode (vehicles with a smart key system).
- Once the vehicle’s engine 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 engine starts, have the vehicle inspected at your Toyota dealer as soon as possible.
Starting the engine when the battery is discharged
The engine cannot be started by push-starting.
To prevent battery discharge
- Turn off the headlights and the audio system while the engine 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 battery is removed or discharged
- The power sliding door (if equipped) must be initialized.
- The power back door (if equipped) must be initialized.
Charging the battery
The electricity stored in the 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 battery may discharge, and the engine may be unable to start. (The battery recharges automatically during driving.)
WARNINGAvoiding battery fires or explosions
Observe the following precautions to prevent accidentally igniting the flammable gas that may be emitted from the battery:
- Make sure the jumper cable is connected to the correct terminal and that it is not unintentionally in contact with any other than the intended terminal.
- Do not allow the other end of the jumper cable connected to the “+” terminal to come into contact with any other parts or metal surfaces in the area, such as brackets or unpainted metal.
- Do not allow the + and - clamps of the jumper cables to come into contact with each other.
- Do not smoke, use matches, cigarette lighters or allow open flame near the battery.
Battery precautions
The battery contains poisonous and corrosive acidic electrolyte, while related parts contain lead and lead compounds. Observe the following precautions when handling the battery:
- When working with the battery, always wear safety glasses and take care not to allow any battery fluids (acid) to come into contact with skin, clothing or the vehicle body.
- Do not lean over the battery.
- In the event that battery fluid comes into contact with the skin or eyes, immediately wash the affected area with water and seek medical attention.
Place a wet sponge or cloth over the affected area until medical attention can be received.
- Always wash your hands after handling the battery support, terminals, and other battery-related parts.
- Do not allow children near the battery.
When handling jumper cables
When connecting the jumper cables, ensure that they do not become entangled in the cooling fans or belt.
To prevent damage to the engine cover
- When removing the cover, make sure that you pull the cover towards you after lifting the front edge to remove the fixed pins.
- When installing the cover, do not force the cover or subject it to strong shocks.
Test yourself
A quick Toyota Sienna quiz: every answer comes with an explanation and a link to the manual page.