Which parts fail
Components named in complaints (automatic and manual transmissions, CVT, axles, driveshaft, 4WD/AWD).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2015 Infiniti Q50 owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2015 Infiniti Q50. The contact stated that while driving approximately 50 MPH, the vehicle began to overheat and smoke was present coming from under the hood. After stopping to inspect the vehicle the contact opened the hood and flames were present in the engine compartment. The contact immediately extinguished the flames using water. The vehicle was later towed to the local dealer. The cause of the failure was not yet determined. The contact indicated that prior to the fire the vehicle had also experienced transmission shifting failures and the front driver's side and passenger side seat belts were locked in the retracted position and could not be used. The cause of the failures was not determined. The manufacturer was not notified of the failures. The failure mileage was 80,000.
The contact owns a 2015 Infiniti Q50. While driving at various speeds, the transmission was slow to shift. The vehicle failed to properly accelerate while depressing the accelerator pedal, and the check engine warning light remained illuminated. The vehicle was taken to a local transmission mechanic to be diagnosed, and it was determined that the gear ratio and speed sensor inside the transmission valve body were faulty, and that the valve body needed to be replaced. The valve body was replaced, and the failure was repaired; however, one week later, the failure reoccurred. The vehicle was taken back to the mechanic, and it was informed that the transmission needed to be replaced. The vehicle was not yet repaired. The manufacturer and local dealer were not contacted. The failure mileage was 99,000.
The contact owns a 2015 Infiniti Q50. The contact stated that while driving at an undisclosed speed, the vehicle stalled. The contact was able to drive the vehicle off the highway and park the vehicle. The contact stated that the failure occurred while the contact was driving on a busy highway. The vehicle was towed to the dealer where it was diagnosed with transmission valve body failure. The contact was informed that the transmission valve body needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and a case was filed. The failure mileage was approximately 74,000.
The contact owns a 2015 Infiniti Q50. The contact stated while driving 40 MPH, the accelerator was depressed; however, the vehicle failed to shift into gear properly, with the check engine warning light illuminated. The vehicle was able to be restarted. The vehicle was taken to an independent mechanic, where it was diagnosed that the transmission valve body had failed, and the transmission needed to be replaced. The vehicle was not repaired. The dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 94,150.
While driving on the interstate and coming over an overpass there was unavoidable debris located in the road. Immediately after passing over the debris there was a loud noise followed by jerking and the RPM's revved up almost like the car was in neutral. I let up off of the accelerator and then tried to accelerate again. The car would not go faster than 30mph and will not shift out of 3rd gear. I had the car towed to the dealership and the diagnostic codes reflected vehicle speed sensor and there was no physical damage that was visible under the car. I was told that the problem was in the transmission and that it would need to be changed and given an estimate that totaled over $10,000. I was also told by the service advisor that this is a known issue with the Infiniti Q50. …
While operating the vehicle, the transmission suffered an abrupt failure resulting in Diagnostic Trouble Code (DTC) P0720 (Output Speed Sensor Circuit). Further diagnostic inspection revealed a complete internal failure of the integrated valve body assembly, which houses the Transmission Control Module (TCM), solenoids, and output speed sensors. The failure caused an immediate loss of gear selection, restricting the transmission to 3rd gear ("limp mode"). Attempting to accelerate beyond 3rd gear causes violent vehicle shaking, severe hesitation, and an inability to maintain traffic speeds due to the TCM losing signal input from the speed sensors and solenoid circuits. This total valve body/TCM failure creates a critical safety hazard. …
The valve body on these cars are useless. Driving down a highway and cant shift out of 3rd gear almost had a car re-end me. Today I am driving and the ECU is not responding I see the check engine light on then I'm like not again. This would be the 3rd valve body I replaced. First I replaced the whole transmission thinking that is what I needed and advised that the valve body and the transmission are one. Yet no they come in parts. Anyways today I am waiting to get home, but the car is not reading my key fob why? Then the ECU and code U0100 is popping up. Something new and turns the car off. The shifting that happen earlier was just a light bulb of I already knew what is wrong. I felt the car shift with a hunch so I looked at my dash board and saw the check engine light again and was like not again. Please not again. Now on the dash board I see AWD and chassis issue. …
I WAS DRIVING MY INFINITI Q50 and puled up to a light. When it turned green I proceeded when I noticed my check engine light comes. It won't shift past 3rd gear. it seems to be in limp mode but there was a tractor trailer barreling down on me. So I get to 35 MPH and ride the side of the road. Once I got home I did a search and apparently there are A LOT of issues with this transmission. Most indicated it was the valvebody and that it could cost upward of $2,500.00 plus there is a back order on them. This is my only car and can't have it tied up to long. I have an appointment to have it diagnosed this coming Wednesday, 06/09/2021. I can't drive it or I will burn up the transmission. If there is such a large problem I would think this would have a recall on it. My car only has 65, 624 miles on the clock. This needs to be addressed. …
While driving my 2015 Infiniti Q50s, the transmission suddenly suffered a catastrophic electronic failure, causing the vehicle to immediately drop into "limp mode." This resulted in a sudden and dangerous loss of acceleration while operating in traffic. A diagnostic scan revealed trouble codes P0500 and P0720 (Output Speed Sensor circuit). However, following Infiniti's official Technical Service Bulletin (TSB ITB19-040), the actual failure was the Transmission Control Module (TCM), which is permanently integrated into the transmission control valve body inside the transmission. Because the speed sensor cannot be replaced independently of the integrated module, I was forced to pay out-of-pocket to replace the entire transmission control valve body assembly and have a dealership program the new unit. …
Transmission, Transmission Valve body, speed sensors. After transmission shifting issues while traveling the interstate I had to have the car towed to the dealership. After the multi point inspection was performed serveral recommended itmes related to the ongoing performance and SAFETY of the vehicle listed below: Transmission $10,446.65 Transmission Valve Body $3693.92 The diagnostic code P0720. Attached is the service bulleting stating they know this will happen and when it does here's how to fix it. Yet they have never recalled the defective transmission. When I contact Infiniti consumer affairs they simply say that they cannot help me because the vehicle does not have warranty. If i had warranty then I would not be reaching out to them for assistance in replacing the transmission.
Related recalls
Power train › Driveline › Driveshaft
Nissan North America, Inc. (INFINITI) is recalling certain 2011-2013 M56, 2012-2013 M35 Hybrid, 2014-2018 Q50, Q70 Hybrid, 2014-2019 Q70, and 2015-2019 Q70L two-wheel drive vehicles. The driveshaft can fatigue and break.
Remedy: Dealers will replace the driveshaft, free of charge. Owner notification letters were mailed August 13, 2024. Owners may contact INFINITI's customer service at 1-800-662-6200.
Transmission complaints in other Q50 years
Frequently asked questions
How common are transmission problems on the 2015 Infiniti Q50?
NHTSA has 39 complaints about the transmission & drivetrain of the 2015 Infiniti Q50, 31% of the model year's 126 complaints. The component named most often is automatic transmission (1 mentions).
Is there a recall for 2015 Infiniti Q50 transmission problems?
Yes — NHTSA recall 24V-470 (driveshaft, Jun 21, 2024). Recall repairs are free at authorized dealers.
At what mileage do 2015 Infiniti Q50 transmission problems start?
Half of the complaints with a recorded mileage happened before about 80,000 miles.
Is it dangerous?
Owners linked 0 crashes, 1 fire and 0 injuries to transmission & drivetrain 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.