Toyota Sienna 2010-2025 Owners Manual: If the engine will not start

If the engine will not start even though correct starting procedures are being followed (, 228), consider each of the following points:

The engine will not start even though the starter motor operates normally.

One of the following may be the cause of the problem:

• There may not be sufficient fuel in the vehicle’s tank.

  Refuel the vehicle.

• The engine may be flooded.

  Try to restart the engine again following correct starting procedures.

  (, 228)

• There may be a malfunction in the engine immobilizer system.

The starter motor turns over slowly, the interior lights and headlights are dim, or the horn does not sound or sounds at a low volume.

One of the following may be the cause of the problem:

• The battery may be discharged.
• The battery terminal connections may be loose or corroded.

The starter motor does not turn over (vehicles with a smart key system)

The engine starting system may be malfunctioning due to an electrical problem such as an electronic key battery depletion or a blown fuse.

However, an interim measure is available to start the engine.

The starter motor does not turn over, 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 battery terminals may be disconnected.
• The battery may be discharged.
• There may be a malfunction in the steering lock system (vehicle with a smart key system).

Contact your Toyota dealer if the problem cannot be repaired, or if repair procedures are unknown.

Emergency start function (vehicles with a smart key system)

When the engine does not start, the following steps can be used as an interim measure to start the engine if the engine switch is functioning normally:

1. Set the parking brake.
2. Shift the shift lever to P.
3. Turn the engine switch to ACCESSORY mode.
4. Press and hold the engine switch for about 15 seconds while depressing the brake pedal firmly.

Even if the engine can be started using the above steps, the system may be malfunctioning. Have the vehicle inspected by your Toyota dealer.