really awful
Crashes / Fires:
1 / 0
Injuries / Deaths:
1 / 0
Average Mileage:
13,407 miles

About These NHTSA Complaints:

This data is from the NHTSA — the US gov't agency tasked with vehicle safety. Complaints are spread across multiple & redundant categories, & are not organized by problem.

So how do you find out what problems are occurring? For this NHTSA complaint data, the only way is to read through the comments below. Any duplicates or errors? It's not us.

2012 Toyota Sienna engine problems

engine problem

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2012 Toyota Sienna Owner Comments

problem #9

Jan 122015


  • 49,000 miles


The contact owns a 2012 Toyota Sienna. The contact stated that while driving 45 mph attempting to engage the brakes, the vehicle accelerated independently. The contact stated that when the brakes were depressed, the vehicle continued accelerated. The vehicle was towed to the dealer, where the problem could not be diagnosed. The manufacturer was made aware of the failure. The failure mileage was 49,000. Updated 4/7/15

- Spring Arbor, MI, USA

problem #8

Feb 052014

Sienna 6-cyl

  • Automatic transmission
  • 25,000 miles
The contact owns a 2012 Toyota Sienna. The contact stated while driving approximately 65 mph, the brake pedal was engaged and the vehicle failed to decelerate. There was a sudden and rapid increase in acceleration. The vehicle was driven off the roadway where the engine was turned off. The vehicle was towed to an authorized dealer for diagnosis however, the technician was unable to duplicate the problem. The manufacturer was notified the defect. The approximate failure mileage was 25,000. Updated 03/20/14 updated 03/21/2014 the consumer stated as traffic began to slow down, he discovered the vehicle would not slow down, when he applied the brake. Updated 04/03/14

- Covington, GA, USA

problem #7

Dec 222012

Sienna 6-cyl

  • 24,000 miles
Toyota Sienna mini van spontaneous acceleration our minivan spontaneously accelerated. I don't know if you know Toyota has been having this issue with older models, but ours is a 2012 Toyota Sienna xle limited all wheel drive mini van. I put on the brake to let my wife out when the van took off as if I had the gas pedal to the floor, yet my foot was on the brake. We kept moving, so I pushed the stop/ignition button and the van would not stop. I then put on the emergency brake and the van was still moving, I watched the RPM's keep going up on the tachometer. I then pushed the off/ignition button again, still would not stop, my next step was to put it in neutral, but I didn't want to blow the engine, so I pushed the off/ignition button again and the engine finally stopped. We were freaked out we had only read about this not thinking it would ever happen to us. Now the biggest problem is I don't feel comfortable having wife drive the van anymore. I called Toyota of nashua, they basically said we can inspect it and call Toyota of California. I called Toyota of ca and they seemed nice and talked about giving us a loaner car. Both Toyota of nashua, nh and Toyota of California both inspected the van and said "there is nothing wrong with the van". they said you can come and pick it up. There are many youtube video showing this problem and even re-enacting the situation, yet Toyota claims user error. I have grown up working on cars for about 35 years, I fixed and driven cars hard. I've done things with cars that most people only see in the movies. I can promise you it was not user error and it was not the floor mats fact!!! beware Toyota & Lexus owners.

- Brookline, NH, USA

problem #6

Oct 122012

Sienna 6-cyl

  • 5,000 miles


Owner was driving and vcs and ABS warning lights came on and stayed on while driving as well as tire pressure light. Brakes on vehicle did not brake as well going down hill. Tires slipped and skidded in the rain on the hills in ventura county. Driver called Toyota and they opened up a case number. Toyota has attempted to fix the vehicle 3 times and cannot determine the reason why the malfunction keeps occurring. Owner has video of the warning lights continuously on while owner is driving. Owner feels this is an extreme safety issue, and believes they were sold a lemon car.

- Carson, CA, USA

problem #5

Oct 272012

Sienna 6-cyl

  • 8,900 miles
While driving on an expressway with steep grades, with the cruise control set, the speed on steep downgrades would increase by up to 5 mph above the speed set on the cruise control. In other vehicles I have driven in recent years, I do not recall the speed variation exceeding 3 mph from the cruise control setting.

- Springfield, MO, USA

problem #4

Aug 172012


  • 2,800 miles
The contact owns a 2012 Toyota Sienna. The contact was driving 15 mph when the vehicle suddenly accelerated. The contact attempted to stop the vehicle but the brakes would not respond. The contact had to shut the vehicle off while it was moving to stop the vehicle from accelerating and avoiding a possible crash. The contact had the vehicle towed to a dealer. The dealer was investigating the acceleration issue. The failure mileage was 2,800. The VIN was not available.

- El Monte, CA, USA

problem #3

May 312012

Sienna 6-cyl

  • Automatic transmission
  • 900 miles


The contact owns a 2012 Toyota Sienna xle. The contact stated that as he approached a stop light, he suddenly experienced sudden acceleration and there was an increase in the engine rpms up to 8,000. The contact forcefully applied the brakes and shifted into neutral. The vehicle then decelerated and the contact drove home slowly. The dealer was notified and towed the vehicle in for a diagnostic test. They were unable to diagnose a failure and attributed it to a driver's error. The manufacturer was notified and offered no assistance. The failure mileage was 900. Updated 08/23/12 updated 08/23/12

- Poolesville, MD, USA

problem #2

May 042012


  • 5,000 miles
The contact owns a 2012 Toyota Sienna. The contact stated that the vehicle abnormally accelerated while the brakes were applied. The contact took the vehicle to the dealer and was advised that there was no failure found within the vehicle. The contact spoke with the manufacturer and was told there would be no further inspections of the vehicle because the dealer was unable to diagnose the failure. The failure and the current mileage was 5,000.

- Hawthorne, NJ, USA

problem #1

Jan 012012


  • 60 miles
The contact owns a 2012 Toyota Sienna. The contact stated that when attempting to brake or accelerate, both pedals would be depressed simultaneously. The contact stated that the two petals were too close in proximity. The manufacturer and the dealer were notified of the failure, but denied any assistance with repairs to the favehicle. The vehicle was not repaired. The failure mileage was 60 and the current mileage was 1,300.

- Columbus, IN, USA

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