2018 Toyota Sienna Transmission Problems

Your 2018 Sienna is making a whining noise when you accelerate, and a mechanic has determined the transmission is failing. At under 140,000 miles, this is unexpected for a Toyota, and repair costs are estimated between $6,500–$7,000. Both the dealer and Toyota have declined to help with warranty coverage or assistance.

Your 2018 Toyota Sienna developed a whining noise and hesitation while accelerating up a hill at 30 MPH around 126,000 miles. A dealer diagnosed the issue as transmission failure. The repair will likely involve transmission servicing, rebuild, or replacement.

Your transmission is making a whining noise, and a P27137F error code has appeared on your dashboard. Your vehicle is currently only operating in 2-wheel drive mode instead of its normal setting. You're worried about driving it because the problem could get worse or leave you stranded on the road.

While driving with children in your van, you experienced a sudden loss of acceleration power and a warning light appeared indicating an electronic control problem with the engine, throttle, or transmission. The dealership diagnosed that both the transmission solenoid and the entire transmission had failed and needed complete replacement, despite regular dealership maintenance and only 89,388 miles on the vehicle.

Your transmission makes a high-pitched whining noise and hesitates when accelerating from a stop in low gear. This appears to be a known issue with this transmission model that may warrant a recall.

Your vehicle makes a whining noise when you're driving and pressing the accelerator. A dealership confirmed that your transmission is failing and needs to be replaced. This will require a complete transmission replacement to resolve the issue.

Your transmission's default economy mode creates a safety concern by starting in a higher gear (3rd or 4th) and limiting engine power from a stop, making acceleration sluggish when turning at stop signs or merging into traffic. The engine struggles (lugging) and won't downshift when you need to speed up, but this problem disappears when you disable eco-mode or switch to sport mode. The transmission programming may need adjustment to allow proper gear selection during these driving situations.

Your Sienna makes a whining or humming noise during acceleration that has been getting worse over several months or longer. You've also noticed a delay when pressing the gas pedal before the vehicle actually accelerates, which has created unsafe situations where other vehicles have nearly hit you from behind. The transmission may need inspection or replacement to address the noise and acceleration delay.

Your 2018 Sienna experienced hesitation during acceleration and displayed multiple warning lights along with a "Pull Over - Take to Dealer" message. The dealer determined your transmission needed replacement, but the repair was not completed. Toyota confirmed your vehicle isn't covered under their transmission support program for this issue, despite the problem occurring at 132,000 miles.

The last week of September 2021 my husband notice a sound like water runing and a leak on the driver and passenger seats, we take the vehicle to the Dealer for an inspection on October 2nd. They said the AC hose was clogged for a spiderweb and the leak can create a mold. This mold can affect my family health. We informed to the insurance and we taked the vehicle to the Dealer for repair. They did an expensive special cleaning to Remove the mold, and disamble my entire vehicle, the worse is my vehicle still unassembled after 3 months at the dealership. All this happens with out any warning sign, symptoms or light. This vehicle is 3 years old and all services on time and by the same Dealership. My vehicle has a lot of technology but not warning about this AC clogged and damage my entire vehicle wich still on repair.

DELAY IN DOWNSHIFTING WHEN THROTTLE IS PRESSED. A DELAY OF 1 TO 2 SECONDS OCCURS THEN ABRUPTLY DOWNSHIFTS AND THE ENGINES REVS LOUDLY.

I WAS TURNING LEFT ON COUNTRY ROAD AT 25MPH THE CAR DECELERATE AND YELLOW WARNING CAME ON THE DEALER SAID THE CAR THOUGHT IT WAS GOING TO ROLL OVER THEY DID THE SOFT WARE UP DATE THE CAR STILL DECALRATE YELLOW LIGHT COME ON MOST OF TIME WHEN STARTING UP

TL* THE CONTACT OWNS A 2018 TOYOTA SIENNA. WHILE DRIVING APPROXIMATELY 45-50 MPH, THE ACCELERATOR PEDAL WAS DEPRESSED, BUT FAILED TO RESPOND. ADDITIONALLY, THE VEHICLE DECELERATED INDEPENDENTLY ON OCCASION. THE VEHICLE WAS NOT DIAGNOSED OR REPAIRED. LARRY H MILLER TOYOTA COLORADO SPRINGS (LOCATED AT 5115 NEW CAR DR, COLORADO SPRINGS, CO 80923, (719) 419-5832) WAS NOTIFIED OF THE FAILURE. THE CONTACT STATED THAT THE FAILURE RECURRED ON SEVERAL OCCASIONS. THE MANUFACTURER WAS NOT CONTACTED. THE APPROXIMATE FAILURE MILEAGE WAS 10,000. THE CONSUMER STATED THE WHILE BACKING OUT OF A PARKING SPACE, THE VEHICLE SUDDENLY STOPPED REVERSING AND THE ENGINE BEGAN TO REV UP AS IF THE GAS PEDAL WAS BEING DEPRESSED. THE VEHICLE WAS PUT INTO PARK AND BACK INTO REVERSE. THE ISSUE RESOLVED ITSELF. THE BRAKING SYSTEM WOULD SHUTTER WHEN IN SNOW OR ICE CAUSING THE VEHICLE TO VIBRATE VIOLENTLY AND LOSE TRACTION. *JS

2018 TOYOTA SIENNA LE. CONSUMER WRITES IN REGARD TO DELAYED ACCELERATION WHICH IS CAUSING TRANSMISSION DAMAGE. *AS *TR

THE VAN STRUGGLES TO ACCELERATE. THERE IS NO WAY TO TURN OFF ECO MODE. NO BUTTON IS AVAILABLE. VAN STRUGGLES TO GO UP HILLS , EXCELERATE THRU INTERSECTIONS AND ALWAYS HUNTING FOR GEARS OR STUCK IN A GEAR AND SOUNDS AND ACTS VERY HEAVY ON POWER TRAIN END. THERE IS AN OPTION TO TURN OFF ECO LIGHT.TURNING OFF ECO LIGHT DOES NOTHING BUT HIDE THE PROBLEM. WE NEED AN OPTION TO COMPLETE DISABLE ECO MODE WITH UPDATE OR WITH A BUTTON.

MY 2018 SIENNA LE IS EXPERIENCING ACCELERATION PROBLEMS. I HAD THE SOFTWARE UP DATED BUT AFTER APPROXIMATELY 1,000 MILES THE PROBLEM IS RETURNING. THIS PROBLEM IS ESPECIALLY UNSAFE WHEN MERGING ONTO THE HIGHWAY.