GMC Canyon won't shift problems

Filed Sep 19, 2026 · Acceleration, Transmission · FL

While i was driving on the highway at 85 mph the truck went into limp mode causing the truck to slow down at a dangerous distance. My body was forced forward causing me to lose a portion of control and causing other drivers behind me to slam on their breaks. I pulled over and turned it off for a few minutes then resumed my travel. About 30 minutes later it happened again at 80 mph the exact same way. After taking it to the dealership they said it was a faulty solenoid in the valve body.

Filed Jul 30, 2026 · Steering, Transmission · CA

On many occasions, over several years of ownership, ''NEW in 2018, the trans has had violent shift Problems. I could only find 1, ONE instance where a person was "injured'' by ANY of the GM 8L transmissions. My neck is hurting Now. I'm compelled to do this for Others who been Scammed by GM as they still sell a 8 speed rewrapped. I can't believe this has been protected against being called a SAFETY ISSUE By any Gov. agency. I got my truck in Retirement and Know I can't and won't Tow a Trailer or Boat Like I planned to. If I cause a wreck, Knowing the Defect, I will be held Responsible, Not GM LLC. It just did something new on 7/23/26. it stuck I a mid range gear and wouldn't shift, I Bumped it into Neutral to slow down and Recover proper control. I've said enough, be safe if you Have an 8 Speed from GM, or a 10 speed too.Read UP.

Filed Aug 14, 2025 · Electrical, Transmission · FL

Transmission has been shuddering since 15,000 miles till now. Dealerships says it's normal on these transmissions, 6 fluid and filter changes and now at 72,000 miles the transmission is failing just outside of warranty. They scammed me and kept my transmission barely alive until warranty ran out and now they want 8k-10k for a replacement. They knew. Dash goes crazy from the touch screen to the digital information screen in the speedometer. They say it's normal and happens on all the units. But it's distracting and has been messing up since bought the truck new. Again they just kept saying it was nothing they can do. Now they say it needs to be replaced after my warranty has run out. DEF system is failing conveniently after the warranty has run out. It's dangerous because they programmed the truck to go into limp mode when anything emissions related fails stranding me anywhere at anytime. Emission failures like sensors should not restrict travel. This is a major issue with the diesels in these trucks and they need to be forced to remove anything that's not dangerous to the health of the engine or drive train from the software or hardware from being able to restrict travel. In every situation I've been restricted to limp mode by dirty particulate sensors, but the code that pops and puts my truck in limp mode says that the NOX sensor is bad. This is false and is just a way for GM to get service at their dealers. Then they charge customers a fortune to replace parts that don't need to be replaced when you can just remove and clean the four particulate sensors and the restrictions will clear themselves shortly after. EMISSIONS RELATED ISSUES SHOULD NOT RESTRICT TRAVEL BY ANY MEANS! It is dangerous to be stranded on a trip because your emission sensors may be malfunctioning.

Filed Jul 3, 2024 · Driver assistance · NY

Constant smell of coolant while stopped at traffic lights or idling even worse when the air vents are on, dealership insists it's because the reservoir cap is vented but coolant reservoir is literally a foot away from drivers window even still shouldn't be smelling coolant it's been like this since a month after purchase. Having issues now with auto braking system activating for no reason did this multiple times almost got rear ended on NY State thruway because it activated with no cars near me once it activates it causes the truck to go into a limp mode (won't go over 30 mph) and starts vibrating like it needs a tune up. The radio and digital display often dissappear for no reason can tell speed. I almost got a ticket from state trooper for unsafe stopping i explained everything and was told i could get a safety violation for defective equipment and to take it garage and drive it till its fuxed , the windows have rolled down a couple of times while it's parked and won't go back up. Headlights often flicker when driving auto low beam/high beam rarely works. Every time it goes to dealership they say they can't duplicate the problem. It's really scary when you're doing 70mph and the auto brake engages. I'm literally afraid to drive it. I have a 14 year old truck with 230,000 miles I don't smell coolant or have these kinds of issues Seems to be a lot of electrical problems going on service advisor said he saw notices for bcm, front facing camera total of 6 issues. Nothing seems to resolve issues but dealerships aren't doing anything just saying can't duplicate problem also paint is chipping every where The issues started around 5300 miles and continuing

Filed Nov 3, 2023 · Fuel system · TX

The high pressure fuel pump broke twice within a 6 month period. The first time, I was traveling at 70 mph in the middle of 100 degree weather in Texas. When I took it to the shop, the mechanic mentioned that the bolt broke inside of the engine and caused the high pressure fuel pump to break and dump gasoline everywhere. It was repaired by adding a new pump and fuel line. After driving it for 5 months, the same issue happened again while driving 30 mph. My safety was put at risk since it was large amounts of gasoline that it was throwing which could have easily caused a explosion/fire. The warning message was a check engine light and the truck going into limp mode. From my research, this exact issue was a recall for the 2018 version of the truck.

Filed Jun 18, 2022 · Fuel system · IN

It keeps putting my vehicle into limp mode with the def system and tell me that I have poor exhaust quality. I can’t keep taking my vehicle into the shop not sure if it’s a sensor or the soot again or what but something has got to give

Filed Jun 16, 2021 · Electrical, Engine · AZ

Have had truck in shop several times, currently in the shop and has been there for almost 3 weeks nobody seems to know what the problem is. Vehicle losses power and goes into a limp mode. Temperature gauge keeps failing, exhaust break does not work, ac cuts out often and does not work often, keeps trying to clean exhaust filter over and over again and again.

Filed May 14, 2020 · Electrical · 50,000 miles · NJ

Truck locked into limp mode suddenly one day and the check engine light came on. The truck was then stuck in one gear. Took it to a mechanic immediately who replaced the fuse box after finding it burnt out. Fast forward a month later, same issue occurs on the road. Both issues occurred while accelerating during a turn. Took to mechanic again to find TCM fuse burnt out and codes p0700 and p2534 present. Mechanic replaced fuse and stretched out wire bundle to see if wiring was an issue. Mechanic also took the truck on a road test to try to duplicate the issue to no avail. As of now the truck is working after the fuse was replaced, however it may happen again in the future.

Filed Apr 16, 2018 · Engine · 14,800 miles · TX

Nox sensor position 2 failed, second occurrence, diesel vehicle entered limp mode. Limp mode is dangerous and indicated def fluid issue. This is a false positive (as described in many places on the internet and by the dealer) as a result of the sensor failure. First dealer did not stock the part, dealer 178 miles away had the part in stock. Limp mode is a continued decrease in vehicle max speed. While a failure of the exhaust system is critical, it should not be allowed to place an owner at risk. By the time I reached the second dealer, I had 4 miles until the vehicle would degrade to 4mph. I was asked to leave without execution of a critical step, because gm documents did not recommend that step as part of the repair. 2 scenarios exist, sensor failure without limp mode and failure with limp mode. In limp mode the vehicle cannot be driven long enough to reset the failure and gm should include this in the remediation. Incrementally, the dealer should have a process to reset limp mode to allow travel without this mode until the next ignition cycle. Also this would be a preferable service from onstar. The limp mode is great for the casual issue but creates a risk to life and limb for travelers and should have limited over ride capability. Being the failure happened on a major highway, in a construction area with concrete barriers on each side this created great stress. No american should own a vehicle costing $41000 that leaves you at risk or stranded. This is irresponsible.

Filed Feb 25, 2017 · Transmission · 1,000 miles · UT

The transmission does not shift properly, when you slow down from approx 40 to 20 then step on the gas the truck has a long hesitation. It is very unsafe and is going to cause an accident. The truck wants to stall out unless you floor it.