Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2012 Toyota Tacoma owners, lightly cleaned up (personal details are redacted by NHTSA).
June 1st 2021 I went to park in a parking space at a local mall. My truck instead of stopping it accelerated out of control jumped two stone curbs, drove though a fence and landed into a swamp. Call Toyota and they have opened a new case # 210602000065. Police report # 21-374-AC. This isn't the first time that this has happen with this truck. It happen in Aug 2019. I contacted Toyota case number 1908060035. They sent out EAA Engineering Analysis Ass. out who did a ACM.CDRX file a month later. Toyota came back said they couldn't find anything wrong and my case was closed. Another incident in winter of 2016 where my truck was stopped and it accelerated on its own and It drove in the 4 way intersection where it caused an accident. lots of damage to cars. Toyota was contacted and they sent me to a dealer for repairs. …
The contact owns a 2012 Toyota Tacoma. The contact stated that while driving, the vehicle failed to exceed 45 MPH. The contact stated that the check engine and traction control warning lights were illuminated. The vehicle was taken to an independent mechanic who informed him about a Special Service Campaign: 20TC01. The vehicle was taken to the local dealer where it was diagnosed and determined that the air injection pump needed to be replaced. The vehicle was not repaired. The manufacturer was contacted and informed him that the Special Service Campaign: 20TC01 had expired. No additional assistance was provided. The failure mileage was approximately 85,000.
Driving on the street to work one morning, the trac off and check engine lights both suddenly appeared. I then noticed that my truck was not able to accelerate past ~40 MPH. Going uphill, my truck was limited to only ~20 MPH. My truck went into this "safe mode." I connected an OBD device and the came up with the following two codes: p2440 and p2442. The codes refer to "secondary air injection system switching valve stuck open" for banks 1 and 2, respectively. I did some further research on the codes, and it turns out this is a common issue on 2012 tacomas. Apparently, the valve for the secondary air injection system is stuck open due to moisture and/or carb build up. I believe this is a design/engineering issue. Part replacement costs ~$480 for each valve assembly. Labor can range anywhere between $200-$500. …
Headed to work to find check engine light illuminated. Truck has less than 41,000 miles. Went to autozone, code reader provided p2442 and p2440 errors related to the secondary air injection system valves. Followed up with local Toyota dealer. Dealer ran diagnostic and found secondary air injection system valves stuck open in banks 1 and 2. Dealer wants to replace parts 17600-0p040: pump assembly; 25710-31022: valve assembly; and the 4 related gaskets, part 17377-31010. Quote was for almost $2400. Again, the vehicle is 2012, less than 41K miles! Researching the Tacoma forums online, this appears to be a common problem with this generation model and more even more so with 2012's. One of the dealer's service advisors informed me that this is also a common problem with tundras. …
I left the gym yesterday and the truck had no power and would not accelerate, I almost got t-boned pulling into traffic. I looked down and the check engine light was on as well as the traction control light. Ran by autozone and had them scan the OBD and it showed p2442 error code. I took it by the dealer this morning and they say both by-pass valves are gone as well as the air injection pump. Estimate was $1,798. This is a 2012 model as seems to be the norm with this failure. But with only 35K miles. I told them this was ridiculous for this to happen on this model with this low of a mileage and that this should be covered under warranty. The service rep said it wasn't and her hands were tied. I talked to the service manager as well as the GM. So far Toyota has refused to resolve this issue in a fair manner. This is a know problem by Toyota on the 2012 model Tacoma's. …
I was leaving work and pulling onto the highway when I noticed my check engine light came on, as well as the trac off light. I went to pull into traffic and immediately realized that whatever was wrong put my truck into limp mode and had a 2500 RPM limit. This was a 60 MPH highway and I couldn't go more than 35 MPH. The traffic coming was immediately upon me and I had to pull over and put on my hazard lights as these vehicles had to slam on their brakes, honk, and swerve around me. I brought it into the dealership and they read code p2442. Which is for a stuck secondary air injection valve. They found water in the valves and they had to be replaced. Doing some research I found this is a very common issue in 2nd gen tacomas, mostly the 2012. This a very well known issue, especially to Toyota, and they have so far done nothing about it. …
The check engine light and the trac off light came on as I was merging onto the interstate. I immediately stopped the vehicle, pulled over, and took my 2012 Toyota Tacoma with 78,000 miles to the mechanic where I left it overnight for them to look at it in the morning. Running a diagnostic they found code p2443 - secondary air injection switching valve stuck. I asked if they had dealt with this before and they said this is a common problem for Toyota and they have done recalls on both the tundra and sequoia models that have had these issues, but the Tacoma hasn't had a recall yet, even though it seems to be just as common with the same parts. They said the cost of parts and labor would be around $2,000. …
Two dashboard lights illuminated at the same time: the check engine light and the trac off light. At first I really didn't notice much of a difference but after 2 days I experienced significant power loss. I would pull out into traffic OK until about 20mph then have no power. It crawled while trying to get up to speed. I read on the internet that if you disconnect the battery and open the gas cap the lights would go out and the problem would go away. I did this and it worked; or so I thought. I then left for an hour trip (I know dumb) and within 15 mins the lights came back on and I couldn't get the truck over 60mph on a major highway. I actually stopped at a rest stop and disconnected the battery and removed the gas cap. Again this shut off the lights but only for about 5 mins. Then the power loss was back. …
Bought truck new in 2012 and maintained 100% recommended maintenance at dealer. At 64,500 mileage, check engine light came on while driving, and we drove truck straight to dealer service garage. Dealer determined secondary air injection pump had contaminated with water, resulting in rust in system (valves also). Replaced pump and valve assembly and gasket. Service advisor said the same parts were used and recalled in response to reports of air induction pump assemblies and/or air injection switching valves issues on their 2007-2010 tundra and 2008-2010 sequoia models, Toyota has decided to increase its warranty on these parts and is even offering a reimbursement if you already had this issue fixed. Tacoma's need to be included in the recall reimbursement! …
I was pulling out on to the highway and my truck failed to exceed 30 MPH with oncoming traffic which nearly caused an accident. Upon inspection by my Toyota dealership, they explained that my secondary air injection valves were stuck open (p2440, p2442) which caused the truck to lose all power. I was then told that since I am no longer under warranty (my truck is only 5 years old with 48,000 miles on it) that Toyota would not cover the 2,000 dollar cost to have the part replaced. Upon further research, countless others were having the same issue. The Toyota tundra also had this issue and an extended warranty was offered for those vehicles. Since Toyota knows this is an issue it is my belief that they should stand by their product and fix the defective part which is a huge safety issue as I found out. …
Engine complaints in other Tacoma years
Frequently asked questions
How common are engine problems on the 2012 Toyota Tacoma?
NHTSA has 124 complaints about the engine & cooling of the 2012 Toyota Tacoma, 42% of the model year's 295 complaints.
Is there a recall for 2012 Toyota Tacoma engine problems?
No. NHTSA lists no engine & cooling recall for the 2012 Toyota Tacoma, though it has 7 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2012 Toyota Tacoma engine problems start?
Half of the complaints with a recorded mileage happened before about 60,000 miles, and 6% before 25,000 miles.
Is it dangerous?
Owners linked 1 crash, 0 fires and 1 injury to engine & cooling problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.