Vehicle Speed Control Problems of Infiniti Q50 - part 1

The transmission speed sensor has failed needs a new valve body. It seems like a very common problem with this car and it’s a $3000 fix according to my mechanic. I think there needs to be a recall issued considering everybody on this website is reporting the same problems.

See all problems of the 2015 Infiniti Q50 🔎.

My car was driving along and all of a sudden the steering wheel got extremly tight and the car was hard to steer, I had to pull over turn the car off and the light was still on, I was like 2 miles away from my house, talking to a neighbor that has same car different year, stated to check recall his call did the samething years ago when we had a cold (low temperature) winter and it was replaced by Infiniti dealer. I never had any issue with this car until now. It's been really cold. Also this car has issues when it rains, it doesn't want to start, I have check out many videos stating the sunroof leaks or tubes for sunroof gets clogged and leaks into the bcm or ecm system causes damage and dash lights. Im not a mechanic but I know that this is something Infiniti/nissian should highly look into. Just a girl,but I know multiple people shouldn't be posting the same concerns on their cars and it's not being looked into.

See all problems of the 2014 Infiniti Q50 🔎.

The car just slowed down super fast on freeway almost got rear ended. It would not go past 3rd gear. Poor acceleration. Could have caused a huge accident. I got it diagnosed and they said it is valve body/speed sensor/tcm and they said this is a common problem for 2015 Q50. I replaced this part 2 years ago and here we go again. Shop diagnosed and said this tcm (transmission control module which is in the transmission) but they have to change whole transmission. Everything happened all the sudden then check engine light came on.

My car wouldnt start and when it did, it would start shaking and every time I accelerate, the speed wasnt going any faster but only the rpms were.

See all problems of the 2018 Infiniti Q50 🔎.

Just over 1 week ago, I was leaving a parking lot and driving back to my home when my car wouldn't accelerate past about ~10-15 miles per hour and wasn't shifting gears. When I took my foot off the gas pedal, the gear just dropped immediately from above third to first gear and the car shook. I first noticed this when already out of the parking lot and pulling off from a median onto the road, with no engine light or other warnings. I quickly pulled into the turn lane where there wasn't traffic and turned the car off and back on. It was the same but luckily I was in eyes view of my apartment, so I drove under 10 mph and made it home. I took the vehicle to a transmission service center and the error code that came up on the computer was (p0500 - vehicle speed sensor a), which the service center said is an issue with the "valve body" inside the transmission, specifically the "tcm - transmission control module" that sits on top of the valve body. I contacted multiple Infiniti service centers and they all confirmed that the valve body for my vehicle (part# 31705-x133a) is back ordered by over a month and could be longer until they have it. They do not sell the transmission control module separately. The valve body was quoted to me for $2200 for the part alone. I attempted to install an aftermarket valve body and a new error code came up on the computer (po720 - output speed sensor circuit). I kept the original valve body and will hold onto it. Doing some more research, this appears to be a common issue with the Infiniti Q50 - [xxx] in addition to the reddit thread above, a quick google search for Infiniti error codes p0500 and po720 point to multiple sources indicating the same common experience and outcome. My vehicle has 110k miles and users in the reddit comments are also reporting the same issue with the tcm transmission control module occurring between 85k - 100k miles in all cases. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

I’m reporting issues with the valve body on a 2015 Q50. I have had to replace the valve body already at cost of $1700. Many others have had same issue as this is a common defect with the tmc part. This needs to be addressed as a recall.

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.

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. After doing researching this a common problem and the consumer is having to pay out of pocket if the warranty has ended. This incident could have ended badly while doing 70mph on the interstate and the car just quits moving. With all of the complaints that I have read over in regards to the transmission issues yet no action has been taken to investigate this problem. It is obliviously a manufacturing issue and the consumer should not have to pay out of pocket for defective transmissions. This luxury car was not a cheap purchase. Very disappointed that with so many cases an investigation has never been done. Infiniti should be held accountable and a recall should be issued for this problem. I will not stop until I can get through to someone that can help.

P07200 code came up, transmission is no good because of a cheap sensor that's impossible to fix. Seems to be very common and very inconvenient.

Vehicle is tramaling or wandering at 50+ mph speeds. Making it dangerously difficult to keep between the lines without constant steering corrections. I have had car aligned and changed the tires. Still issue persists. There are several post online about this issue with the Infiniti q60 and Q50 models.

See all problems of the 2019 Infiniti Q50 🔎.

The transmission valve assembly control module and vehicle speed sensors have both failed. The car will not shift out of 2nd gear and cannot go faster than 40 mph. This is a safety issue. I had my car inspected by a certified mechanic and he diagnosed the problem. He also stated that that he has seen this a lot with Infinitis. I have maintained my car well but this is not a maintenance issue. There are thousands of Infiniti owners online stating that they had the exact same problem. I filed a case with Infiniti #52260861. This is a design flaw with all Infiniti cars and SUV's and it should be a recall or at a minimum fixed for free by Infiniti. It cost me $3,500 to have my car fixed and this should be paid by Infiniti to me and all other Infiniti owners with this same problem.

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.

Valve body failure.

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.

Traction control did not function when needed. I had my breaks and rotors replaced two days prior to the accident, which may have had an impact on the performance of the vehicle. Insurance representatives did look over the vehicle, as it is now in their possession. However, I do not feel as though they took the time to look into my concerns. There was no warnings on the dash.

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 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.

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.

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.

Speed sensor is faulty on Infiniti Q50. . . Had it replaced 9/28/22 for 3700. 00 now on 3/03/23 I was told I need to replace the transmission for 7300. 00 I research speed sensor it seem 2014 to 2015 Infiniti Q50 are having issues with speed sensor. I have read multiple complaints about this issue. It should be a recall on the speed sensor. Infiniti/Nissan know it I will never purchase a another Infiniti/Nissan vehicle again.

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.

I brought a lemon from premier auto kc out in kansas city, kansas! I was sold a lemon and have had major problems with the car since.

The contact owns a 2014 Infiniti Q50. The contact stated while driving approximately 45 mph, the vehicle independently decelerated to 10 mph. The contact depressed the accelerator and observed that the rpms was elevated however, the vehicle failed to respond. The contact pulled off the road into a parking lot and turned off the vehicle. The contact stated that when she restarted the vehicle, the vehicle jerked while driving and failed to exceed 20 mph. The contact stated there was no warning light illuminated. The vehicle was taken to the local dealer where it was diagnosed and determined that the valve body assembly needed to be replaced. The vehicle had not been repaired. The manufacturer had not been informed of the failure. The failure mileage was approximately 133,000.

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 .

I purchased a new 2021 Infiniti Q50 from Infiniti of cool springs on September 28, 2020. There was an incident on January 13, 2022 due to a manufacturer defect that caused my car to accelerate on it’s own. I was parked at a car wash to vacuum my vehicle. I had my foot on the brake to move the gear shift into park when my car rapidly accelerated which caused me to crash through a metal fence that separated the car wash from the adjacent property. I have an added safety feature on my vehicle to prevent a forward collision with emergency breaking that also didn’t implement. There wasn’t any warnings, indications or symptoms beforehand. I had my Infiniti for 16 months with only 20,766 miles on it at the time of the incident. This malfunction could present a serious public safety issue. I or someone else could have been seriously injured in a different scenario. It was fortunate that I was stopped and no one was in front of the car. Nissan issued a recall on April 3, 2021 for the problem of rapid acceleration. The dealership without my knowledge completed the recall on my vehicle on April 1, 2021 which evidently didn’t fix the problem. Nissan and the dealership have been and are therefore aware of the problem. Infiniti consumer affairs nor the dealership want to assume any responsibility for the malfunction. An inspection has not been performed yet. Infiniti consumer affairs requires me to assume responsibility for the cost of a rental during the 6 - 8 week inspection of my vehicle along with the cost of any storage fees. The vehicle can be inspected at Infiniti of cool springs. It’s been there since the incident.

See all problems of the 2021 Infiniti Q50 🔎.

I have 3 issues with the car. The braking issue presented itself last in time but is most important relative to safety. Around mid January 2022, my car, while I was driving, and without any notice, began to decelerate/brake for no reason. My car is equipped with front driver assist but there were no cars, hazards, in front of me. It was a clear, dry day and the car was warm. It was momentary and fortunately no one was behind me. The car beeped, but there was no other warning. The second time this same event happened, however, the accelerator pushed back against my foot. Again, no one was in front of me and it was a clear, dry day. The third time this happened, the car beeped and what I know now is the cruise control indicator, appeared on the display. I did not touch the cruise control to activate. The other two issues were that both display screens were blacking out and rebooting while driving, for no apparent reason. The other issue is with the sirius xm satellite, which is not functioning properly. I have informed sirius xm of this issue as well. Given all of these issues, possibly all electrical, I contacted my local Infiniti dealer to assess, with special concern for the random braking issue. The car was assessed and they could not duplicate any problems. They mentioned that perhaps if they had more time they may be able to duplicate the problems. The following Monday, I took the car to the dealership and left it overnight for assessment. I was called the next day and advised that they could not duplicate the issues. The dealership returned the car without making any repairs, diagnoses, or being to able to duplicate problems. Since the car has been returned to me, it has continued to have problems. The braking issue has happened twice since, with one time involving the accelerator pushing back. The screen has blacked out and gone into parking mode, while I was driving. I have contacted Infiniti corporate to advise of problems.

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.

Chassis control system error message comes up. Normal driving. Parked and next day error message displays. Driving not yet affected. Dealership says they know of error message.

See all problems of the 2016 Infiniti Q50 🔎.

Forward emergency braking (Feb) activating when not needed. January 11th 2020 first day of owning infniti Q50 luxe 3. 0t no packages, only Feb (which is standard on all Q50 now) driving home from kelly Infiniti of denvers, MA dealership. Allen rd extention - speed limit 30mph, slightly windy road, wet, possibility of black ice. All of a sudden, with not a single car ahead of me and no cars going toward me - car starts to brake like collussion to some imaginary object is unavoidable. Was able to stay on the road. Few days after that - driving from nashua, nh to my house at 159 allen rd by highway rt 3 (55 mph). Driving in the middle lane, switching into the left lane to pass slow moving car in middle lane. There are two cars in the left lane and plenty of space in between them. Distance to the car ahead of me in left lane is about 10-12 yeards. To the car behind - 15-20 yeards. All of a suddne when I already moved into the left lane car starts to brake like there is no tomorrow, car behind me almost rear ended me. What was worse - the person in that car thought I did that on purpose and crazy person starts to chase me sitting dangerously close to my rear bumper. Then he/she passes me and hits the brakes in front of me - I barely avoided rear ending that car at highway speed. Friday January 24th 2020 driving on rt 3 (speed limit 55mph) driving in the right lane, slow moving truck in front of me, changing lane to the left (middle lane), in the process of passing the truck - already driving by the truck's side - all of a suddne car starts to brake so hard that car stats to sway and I see in the right rear view mirrow that trunk of my car is under the truck. Mirciously I was able to manage to escape this situation. This car with this technology is unsafe to drive, it will cause more accidents than prevent.

See all problems of the 2020 Infiniti Q50 🔎.

First instance: while driving on the highway going 60mph my car powered down, preventing me from controlling the car. The gauges and lights inside the car went dark and mph went to 0. I lost electrical power and after 1 minute the car is back to normal. Second instance: as I was pulling into a driveway and went over a bump the car lost power and powered down, I naturally pressed the gas before I understood what was wrong, the car powers back up as I'm pressing the gas and caused me to almost hit another car.

I purchased my 2017 Infiniti Q50 as a certified dealer owned vehicle with 4710 miles on it from airport Infiniti on 12/31/2018. Since taking possession of the car, I have had three separate instances where my car lost power during acceleration, in which one of the instances nearly caused me to be hit by a semi-truck when crossing a divided highway. I have provided videos to the manufacture but they have refused to take action because the vehicle does not set any dtc codes. When this condition happens my 3. 0t Q50 accelerates extremely slow even with 100% throttle. The net result is that when I intend to cross a divided highway, I experience a 1-1. 5 second delay from the time I push down the accelerator to when the car begins to move, then the acceleration from 0-15mph can take upwards of 5-6 seconds. The resulting feeling is a car that rolls into a dangerous intersection and exhibits stall like conditions. Only once did the car set dtc codes during this instance. The codes set were b130d, c1a16 and po340. These codes set the first instance, but have not set during the past two occurrences of the same acceleration issue. These instances are completely random which make them extremely dangerous. For instance, the car will be driving completely normal, I will stop and an intersection and then when I go to turn out into the intersection, I go into this stall condition without warning. The dealership has had the car 4 separate times and each time they have refused to fix anything on the car, despite having a video of the occurrence and confirming that the acceleration was entirely abnormal. I have no choice but to drive this car if Infiniti refuses to fix it, but feel it is likely that it will cause injury or death to me and my family if I drive it. I have attached a summary of the daily log I have been keeping since I purchases the car on 12/31/2018.

See all problems of the 2017 Infiniti Q50 🔎.

While accelerating, the driver switched the vehicle from manual shift mode to automatic. The driver noted a significant increase in measured rpm via the tachometer as if the vehicle "jumped into a lower gear or failed to find a gear. " the driver noted that the rear tires lost traction, causing the car to turn towards the left. Shortly after, the driver lost control of the vehicle and crashed.

I am experiencing software related issues that have become increasingly dangerous. In sum, the Infiniti software shuts down or locks up forcing me to become an it technician while driving. When the software shuts down, I lose the speedometer, tachometer, climate control and audio control. Here's an overview of my experiences for the past 3 years: randomly, the software will shut down leaving me without my instrument panel (speedometer, tachometer), climate control and audio control. Randomly, the software will lock up leaving me without climate control or audio control and the only resolution is to pull over, shut down and restart the car randomly, climate controls are set to 60 degrees w/ ac yet hot air is blowing out of the vents. Most recently, the onboard clock that displays the date and time will reset to 01-01-2012 and the clock will start at 6:00 am. The only resolution is to reset the date and time. This seems to occur every 3 or 4 weeks. When I call the service department I'm asked to bring in the vehicle only to be told that all updates have been applied and the issues cannot be duplicated. I have taken and posted several youtube videos showing the problems-which I'll admit is very dangerous to do while driving. In fact, I firmly believe that when these software issues occur, I am forced to play the role of an it technician and troubleshoot the issues while driving which is incredibly dangerous. These issues occur randomly while driving. This is a lease vehicle and I plan to return early as the continued issues put me and my family in danger.

I have complained to Infiniti several times throughout the 6 months I've had the vehicle. I noticed after a few weeks of leasing the car that when I steer almost to a 90 degree angle whether it be out of a right or left turn the car loses acceleration. This happens on a daily basis, not every time I turn, but more times than none it loses considerable acceleration which has almost caused a wreck. To me this is a major safety issue. I've never experienced this in an other vehicle I've driven. Infiniti says it's a traction control issue that disengages the throttle when the computer feels the rear wheels will spin out of control. This loss of acceleration happens at low speeds and usually pulling out of a shopping center either right or left. At low speeds this should not be a safety response.

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.