2015 Infiniti Q50 Speed Control & Cruise Problems

The valve body went bad at 164k miles. Im not the only one. On all the forums and fb groups im on, there are hundreds of valv bodys going bad on the q50s for this general area of the year. On my facebook group i have seen 4 people in the past 2 days with theirs going out. Code p0720. Mine is being hauled to the shop right now so i dont have paperwork of replacement at this time for a few days

P0500 vehicle speed sen/cir P0720 a/t veh speed sen/ circuit-or- output speed sensor P1574 ascd vhcl apps sensor - or lcc vhl spd sen (icc models) My safety was put at risk when the vehicle hesitated and stop changing gears while traffic was behind me. The vehicle was inspected by a local dealership which was Nissan and also Infiniti including a transmission shop named ammco. There were no warning lights that would indicate the vehicle was failing until April the 5th

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.

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

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.

CAME TO A SLOW STOP AT A RED LIGHT IN MY 2015 INFINITI Q50. MY FOOT WAS DIRECTLY ON THE BRAKE. WITHIN SECONDS THE CAR BEGAN TO PULL FORWARD AND I APPLIED ADDITIONAL PRESSURE ON THE BRAKES BY USING BOTH FEET. THE ENGINE WAS RACING OUT OF CONTROL AND THE TIRES WERE SCREECHING. SIFTING THE GEARS DID NOT HELP. I LET OFF THE BRAKE AND TURNED RIGHT INSTEAD OF STRAIGHT IN ORDER TO AVOID HITTING CARS. SHIFTING VIOLENTLKY THE CAR FINALLY WENT BACK TO NORMAL. THE DEALER DENIES THE CAR IS AT FAULT AND SAYS THIS IS A CASE OF HUMAN ERROR.

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.