2018 Toyota Sienna Reliability Score & Common Problems

Owners of the 2018 Toyota Sienna report issues primarily related to the electrical system, with problems including odometer discrepancies and malfunctions in the safety connect system. Complaints frequently mention the master warning light illuminating and the vehicle stalling at approximately 56,000 miles, with one incident linked to a recall involving the electrical system. Additionally, multiple owners describe malfunctioning power seats in the third row that activate unexpectedly while the vehicle is in motion, posing a safety risk. These issues occur at varying mileages and can impact vehicle operation and passenger safety.

Owners of the 2018 Toyota Sienna frequently report issues with air bag deployment during crashes. Complaints highlight that in several incidents involving both high-speed and low-speed collisions, the front air bags did not deploy, although side air bags did in one case. These incidents often occur at mileage ranging from 60,000 to 117,000 miles. Safety implications are significant, with reports of crashes leading to injuries, including bruises, concussions, and potential fractures. Buyers considering this model should be aware of these reported air bag deployment failures in the event of a frontal collision.

Owners of the 2018 Toyota Sienna frequently report issues related to the vehicle's structure, specifically with the front bumper and sliding doors. Multiple owners describe the front passenger side bumper snaps coming undone, leading to damage of the supporting plastic frame, particularly after contact with curbs. Complaints also highlight problems with the automatic sliding doors, which lack an emergency stop feature, posing a potential safety risk if something obstructs their path. Additionally, one report mentions the driver-side carpet being loose and interfering with pedal operation at around 4,700 miles. These issues, particularly with the sliding doors and bumper, could have safety implications if not addressed.

Owners of the 2018 Toyota Sienna report issues related to the fuel system, with primary concerns involving vehicle acceleration and recall repair delays. One owner describes a scenario where the vehicle fails to respond to the accelerator pedal while driving at highway speeds, occurring at approximately 52,350 miles, even after a recall repair was reportedly completed. Another owner notes the vehicle surging forward unexpectedly when idle, with an unknown warning light illuminated, at around 2,000 miles. Multiple complaints highlight the unavailability of parts needed for recall repairs, with some owners expressing that the manufacturer has taken an unreasonable amount of time to address these issues. No reports of crashes, fires, or loss of control are mentioned in the complaints.

Owners of the 2018 Toyota Sienna report issues related to engine performance and oil levels. Complaints frequently mention the vehicle jerking and losing power while driving, with some instances of the vehicle shutting off independently, even after a fuel pump replacement. These issues appear to start as early as 2019 and persist despite multiple attempts at repair. Another reported issue involves the oil warning light illuminating and low oil levels being detected, occurring at low mileages around 3,700 miles. There are no reports of crashes or fires associated with these complaints, but the loss of power could potentially affect vehicle control.

Owners of the 2018 Toyota Sienna report issues related to vehicle speed control, with two distinct problems emerging. One complaint describes a malfunction involving the torque converter clutch pressure control solenoid circuit, which occurs when the vehicle reaches speeds of 85 mph. Another owner reports unintended acceleration while reversing, resulting in a crash when the van unexpectedly went full throttle. These issues suggest potential safety implications, particularly in scenarios involving loss of control during reversing maneuvers. Buyers should be aware of these reported problems, especially if considering a vehicle with similar mileage or usage patterns.

Owners of the 2018 Toyota Sienna report issues with seat movement, particularly in the rear rows. Complaints frequently mention that the rear seats move independently, even when the vehicle is stationary, with some describing lateral and twisting movements. One report highlights concerns about potential safety implications, noting that the seat movement could affect the integrity of the LATCH system and seat belts, particularly in the third row. These issues are noted at low mileages, around 1,000 miles, suggesting they may occur early in the vehicle's life. Used car buyers should be aware of these symptoms and consider inspecting the seat mechanisms, especially if the vehicle has been used to transport children or multiple passengers.