2012 Toyota Sienna Service and Repair Manual

Two engines were offered in the 2012 Toyota Sienna: the 2.7L four-cylinder (1AR-FE) and the 3.5L V6 (2GRFE). Which one is under the hood changes the service specifications on almost every powertrain job, so the code cast into the block is worth confirming on this van before a single fastener comes out.

Engines

• 2.7L 2700CC l4 GAS Naturally Aspirated
• 3.5L 3456CC V6 GAS DOHC Naturally Aspirated

Trims

• Base, Van Cargo
• Base, Van Passenger
• LE
• Limited
• SE
• XLE

Known issues on the 2012 Sienna. Eight recalls sit on the federal record for this vehicle. Two are label campaigns: in one, incorrect information on the vehicle placard may lead to tire overloading; in the other, an inaccurate label could lead to owners overloading their vehicles and tires. Three are air bag campaigns. Two of those cover the passenger-side frontal inflator module — in one, an inflator explosion may result in sharp metal fragments striking the driver or other occupants; in the other, an inflator rupture may result in metal fragments striking the vehicle occupants. The third covers the frontal air bag sensor and control module, where the front passenger seat occupant sensing system is out of calibration. One covers the door structure: if the power sliding door opens while the vehicle is moving, there would be an increased risk of injury. One covers electrical equipment on vans fitted with non-original-equipment remote engine starters, where antilock braking and stability control may be lost. The eighth covers hydraulic service brake hoses on wheelchair vans built on the Sienna, where contact may cause failure of the rear brake hoses, resulting in a loss of vehicle control. Owners have filed 331 complaints against the 2012 Sienna, and 138 technical service bulletins have been published for it.

Work on a van this age tends to land on the same systems those campaigns name — the sliding doors, the occupant-sensing front seat, the rear brake hoses — and on each of them the number that settles the job is the one Toyota published for the 2012 Sienna, not one carried over from an adjacent model year.