A P0302 code on your 2021 Toyota Sienna indicates the engine control module detected misfires in cylinder 2. The 2021 Sienna transitioned to hybrid-only powertrain with a 2.5L Dynamic Force engine, requiring specific diagnostic considerations.
2021 Sienna Hybrid Powertrain
The 2021 Sienna exclusively uses the 2.5L A25A-FXS engine paired with hybrid motors. This Atkinson-cycle engine provides efficiency while the hybrid system supplements power. Cylinder 2 is on the front of the transverse-mounted engine.
Misfire in Hybrid Context
The Sienna's hybrid system monitors engine operation closely. Misfires can affect hybrid coordination, potentially causing the system to rely more on electric assist and reducing overall fuel economy.
Common P0302 Causes
Typical causes include ignition coil failure on cylinder 2, spark plug issues, fuel injector malfunction, and intake valve carbon deposits (the 2.5L uses some direct injection). The hybrid's frequent engine start-stop cycles can affect ignition component wear.
Diagnosis Approach
The coil swap test works effectively on this engine. Cylinder 2 is accessible from the top after removing the engine cover. Check warranty status first—the 2021 may still qualify for coverage.