2015 Infiniti Q50

My car would not accelerate over 40 mph randomly after work. Once i noticed and tried to shift to a lower gear the car did not shift gears at all. When these things first happened there was no indicator lights on. The next morning the check engine light came on and the code pulled was P0720. After finding a repair shop to look further into the issue I was advised the car needed a new transmission to fix the issue. $4,000+ for the repair and as i google the issue I see that this is a common issue and it seems to always happen unexpectedly side note: also should be a recall on driver side blend door.. i almost died this summer due to cold air only blowing on one side in the middle of summer in 100• degree weather.

The contact owns a 2015 Infiniti Q50. The contact stated that while driving at highway speeds, the vehicle inadvertently slowed down. The vehicle failed to accelerate. The check engine warning light was illuminated. The vehicle was towed to the local dealer where it was diagnosed that a valve body replacement was needed. The vehicle was not repaired. The manufacturer was contacted, and the contact was informed that the vehicle was not covered under warranty. The failure mileage was approximately 56,000.

The speed sensor on car seems to have failed unexpectedly while driving over a bridge. The car would barely move and could have become a dangerous situation for multiple people had it been typical traffic. The issue seems to be that although the sensors are corrupted, the entire valve body or transmission must be replaced to solve the issue leaving the car inoperable. The car is currently at a repair shop. The engine light did come on shortly after. PLEASE ISSUE RECALL. https://static.nhtsa.gov/odi/tsbs/2019/MC-10168892-0001.pdf

4/16/2023 Sunday 5pm With my wife and daughter in the car, I started the vehicle in my driveway and selected Sport mode as usual. Selected reverse and backed into our turnaround then forward to the end of our driveway. Driveway is approximately 4 car lengths long with a 20 ft long apron turnaround. Almost immediately after braking at the end of the driveway while waiting for passing traffic to exit drive, vehicle suddenly accelerated and I immediately pressed the brake as hard as I could to prevent driving into passing vehicles. I could hear the tires trying to grip/spin while I was fighting to press the brake harder to hold it t back. I then panicked and selected the gear shifter to anything other than drive and it immediately did the same in reverse. After getting in into park, I immediately selected Standard mode and the vehicle performed normal afterwards. There were no warning lights or anything to indicate any issues. Previously I had noticed minor intermittent issues of high RPMs when slowing or braking while in Sport mode but it would immediately correct itself. I have not had a chance to take it for inspection as it's now Monday morning April 17. We were all very shaken. Please advise.

The car was being driven on a normal day and while in gear and driven the car stalled and would no longer shift automatic. The car will not come out of 3rd gear. Took the car to repair shop and was told is a known issue with this model and even the transmission or transmission valve body needs replacement. Infinite will not issue recall and I have reach out to corporate on the issue the repair want 8,000 to replace transmission the car is out of extended warranty that was purchase on the vehicle I’m only the second owner of the car well maintained and should not be having this issue of a self maintained transmission with a vehicle worth 25,000 wen brought.

My Car Suddenly Stopped In The Middle Of The Road With A Check Engine Light. I Have a P0720 & P0500 Codes Indicating A Vehicle Speed Sensor & Output Speed Sensor Failed While Operating . This Cause My Transmission To Fail And Not Shifting. I Am On My Way To The Dealer Now . Hopefully Infiniti Will Do The Right Thing And Fix It . At 56,000 Miles A Transmission Should Not Fail . Unexpectedly Almost Causing A Car Collision . No Prior Warning Was Provided By The Car . The Car Just Suddenly Failed . This Is A Very Serious Safety Concern .

When on the highway my transmission slipped then went out and wouldn’t accelerate, without any warning or sign of trouble beforehand. I scrambled to pull over and it started to accelerate again. It struggled to shift in 1st gear and second but despite going over 40 mph it would not shift to third gear. I could feel it slipping/sputtering when letting up on the accelerator and jerk when I press on the brakes. The engine will continue to rev high at lower speed. My check engine light came on and gave two codes, P0720 and P0500. I took this to my mechanic and he advised the valve body that houses the AT speed sensor be replaced and I likely need a new transmission. On a forum for Q50s another Infiniti owner said a dealer parts manager told them that Infiniti was aware there was a problem, and that the valve body was hard to come by and part of the delay was due to them redesigning the part to assure it didn't happen again. They suggested filing a case with Infiniti in case they were to issue some type of recall or TSB. He said out of the 750+ parts that were on backorder, his was #130 in line, and it still took over 2 months to receive. IF this is a known issue it is dangerous and should be addressed

TL* THE CONTACT OWNS A 2015 INFINITI Q50. THE CONTACT STATED WHILE DRIVING APPROXIMATELY 70 MPH, THE VEHICLE JERKED, SHIFTED GEARS, REDUCED SPEED, THE ODOMETER FLASHED, THE CHECK ENGINE WARNING LIGHT ILLUMINATED, AND THE HEATING AND AIR CONDITIONING SYSTEM WENT FROM COLD TO HOT. THE CONTACT GOT OFF THE NEAREST EXIT AND PULLED OVER AND WAITED A WHILE BEFORE CONTINUING TO DRIVE HOME TO PARK THE VEHICLE. THE CONTACT STATED THAT A DIAGNOSTIC CODE READER RETRIEVED DTC CODE: P0720 (OUTPUT SPEED SENSOR). THE CONTACT CONTACTED INFINITI OF TAMPA (4600 N DALE MABRY HWY, TAMPA, FL 33614; (813) 694-1579) AND WAS INFORMED THAT THE CAMSHAFT NEEDED TO BE REPLACED. THE VEHICLE WAS NOT REPAIRED. THE MANUFACTURER WAS NOT MADE AWARE OF THE ISSUE. THE APPROXIMATE FAILURE MILEAGE WAS 65,000.

WAS DRIVING MY INFINITI Q50 ON A NORMAL DRY DAY WHEN ALL OF A SUDDEN IT DOWN SHIFTED OR FELT LIKE I WAS DRIVING A STANDARD MODEL VS AUTOMATIC... I PULL OVER MY ENGINE LIGHT COMES ON.. I TURNED OFF ALL SENSORS ASSOCIATED WITH THE INTELLITOUCH SYSTEM THINKING IT WAS NOT JUDGING THE DISTANCE CORRECTLY BETWEEN CARS BECAUSE IT WILL AUTOMATICALLY SLOW YOUR CAR DOWN... CONTINUED DRIVING AND I'M NOTICING AS I TRY TO ACCELERATE MY CAR IS NOT SHIFTING INTO 3RD GEAR... SO I GET TO ABOUT 35-40 MPH AND NOW I CAN TELL IT'S REVVING IN THE SAME GEAR..GET HOME GOOGLE THE ISSUE AND IT SEEMS THE VALVE BODY ON THE 2015 Q50 HAS A THREAD... GO TO YOUTUBE THIS GUY HAS A VIDEO ABOUT HIM BEING TOLD IT'S THE SPEED SENSORS... BUT WHEN HE WENT FOR REPAIR INFINITI INFORMS HIM THE VALVE BODY NEEDS REPLACING. I TOOK MY CAR INTO AN INFINITI DEALER , SPENT $180 TO HAVE A DIAGNOSTIC RUN AND WAS TOLD THEIR IS A SERVICE BULLETIN FOR THE SPEED SENSORS THAT THEY SHOULD JUST REPLACE THE VALVE BODY. THE VALVE BODY IS $1635 AND ON A NATIONAL BACK ORDER AS OF AUGUST 2020 WHEN I'M EXPERIENCING THIS ISSUE.. CALLED INFINITI CONSUMER AFFAIRS AND I'M TOLD WELL UNLESS YOU PAY FOR THE PART WE CAN'T DO ANYTHING TO GET IT EXPEDITED... IT'S BEEN 45 DAYS... SO I HAVE TO TIE UP $1700 AND DON'T KNOW WHEN THIS PART MAY BE AVAILABLE.. CAN'T DRIVE CAR BECAUSE I'LL BURN MY TRANSMISSION UP... THE VALVE BODY IN 2015 Q50'S NEED TO BE RECALLED...I COULD HAVE BEEN ON THE FREEWAY OR DRIVING TO OR FROM LOUISIANA FROM HOUSTON.. LUCKILY I WAS WITHIN 15 MILES OF MY HOME.. CALLED THE OTHER 2 INFINITI DEALERS IN HOUSTON NONE OF THEM HAVE IT IN STOCK AND HAVE AT LEAST 1 Q50 WAITING FOR REPAIR.. CALLED THE DEALER IN AUSTIN ALSO NO STOCK WITH 2 VALVE BODIES ON RESERVE... I HAVE 106000 MILES ON MY Q50 AND IT'S NO LONGER UNDER WARRANTY.. THIS ISSUE HAS BEEN REPORTED AT FEWER MILES LIKE 30K-50K SO HAS NOTHING TO DO WITH THE AGE OF THE CAR.

ENGINE AND/OR TRANSMISSION LOST TORQUE POWER. SINCE 2016 WHILE CAR ONLY HAD 11,000 MILES ALL OF THE SUDDEN CAR LOST TORQUE POWER WHILE ACCELERATING. CHECK ENGINE INDICATOR HAS NEVER LIGHT UP AND DEALER CONSULT SCANNER HAS NEVER FOUND THE ISSUE. STILL CAR DOESNT HAVE SAME ACCELERATION NOR TORQUE WHILE GOING 0-60MPH. ALREADY I'VE SEEN SO FAR 4 CARS OF THE SAME YEAR WITH SPEED SENSOR PROBLEMS AND REPLACEMENT. MECHANICS SAY IT BEGINS BY LOOSING POWER UNTIL STOPS WORKING AND CAR WONT MOVE.