2018 GMC Canyon Problems

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.

This is a known problem with GMC and Chevy trucks, known as the Rumble. At approximately 45mph and up, the truck feels like it’s going over rumble strip and the back end is slipping. This causes the steering wheel and truck to shake. It could result in the loss of control if it gets too bad. I took it in for diagnostic testing, which confirmed that it was the transmission. They recommended a triple flush and replacement of the transmission fluid, as well as a computer upgrade. I had them complete the recommended service. As of right now it seems to have helped. But if it returns the next steps is to replace the torque converter. There were no warning lights, nor messages indicating an issue.

The contact owns a 2018 GMC Canyon. The contact stated while parking the vehicle, the ignition key was difficult to remove from the ignition cylinder. The contact stated that the failure was constant and was unable to remove the key from the ignition cylinder, causing the 12-Volt battery to be drained. The contact had taken the vehicle to a local dealer, where it was diagnosed and determined that the contact needed to jiggle the key until being able to remove the key from the ignition cylinder. The vehicle was not repaired. The manufacturer was not informed of the failure. The failure mileage was approximately 38,000.

The contact owns a 2018 GMC Canyon. The contact stated while the vehicle was parked, the contact attempted to remove the key fob from the ignition, and the key fob was stuck. There was no warning light illuminated. The contact stated that the gear shifter was in park(P) but the contact was unable to remove the key fob. The contact restarted the vehicle and shifted into other gears several times to remove the key fob. The vehicle was taken to the dealer where it was diagnosed that the gear shifter assembly had failed and needed to be replaced. The vehicle was repaired; however, the failure recurred. The vehicle was taken back to the dealer where it was not diagnosed or repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 32,500.

My 2018 GMC Canyon just underwent repairs due to a crack in the head gasket. A serious issue which resulted in having to take said GMC Canyon to a mechanic before further damage to the engine could be suffered. My truck only had a measly 76,000 miles. Definitely, something GMC should take a look into. I however was fortunate enough to notice abnormal loss in the coolant reservoir before suffering excessive overheating or potentially an engine fire. At such a low mileage as well as the nature this issue GMC should take pride in ensuring reliability and care for the customers that experienced this manufacturing defect.

2 weeks ago I was driving on the highway doing 65 mile per hour and suddenly my truck started shaking and. Suddenly completely shut down lost power brakes stiffed and steering wheel as well. I safely pulled over to try to restart the vehicle and on my dash board light came on engine, TCM light and a light with a little car with hash marks called dealer the technician said it was a ecm. Problem and that am looking at a price of 7,000 dollars which is not in my budget reaching out to see if is maybe a manufacturing issue

The warning light is saying engine power reduced having to do with the DEF system

Major potential for deadly fire or explosion. Fuel tank strapped failed after forward strap bolt fell out of threaded cross member where fastened in frame. The failure led to the fuel tank hanging inches off the ground on the freeway stressing fuel pump lines to forward upper tank. Metal grinding noises heard to prompt roadside inspection confirming hanging, unsecured tank full of 26gal of diesel. The tank wedged the fuel tank strap between plastic tank and drive shaft (propeller shaft) with heat and potentially spark as the the metal strap ground into the drive shaft marring and striating the durable metal. Heat and plastic melts, heat and spark with diesel combusts..in addition to risking of dragging tank at highway speed rupturing tank. Upon service at the dealer, mechanic observed the rear bolt to fuel strap was also loose and needed to be secured. GMC Protection Plan denied compensation for coverage as they do not cover "bolts, fuel straps, or manufacturer defects" under advertised "Bumper to Bumper" GMC Protection Plan marketed by GMC dealerships as protection for all non-wearable parts. No warning indicators appeared. My dog was in the truck bed in a camper shell directly above the potentially massive fire or explosion, this could have been catastrophic if it had been ignored. Additionally I was in northern California and southern Oregon when issue presented- potentially causing a major forest fire incident. While my outcome was fortunate in terms of safety, this could claim lives and even massive incidental loss of property. Vehicle has been inspected by local dealer and GM notified, hoping to receive coverage for damaged parts. Interestingly, there was previously a GM recall involving forward fuel strap dislodging and wearing into drive shaft on previous years of GM vehicles. No notable corrosion observed, bolts in question are high on frame secured to protected cross members, occurred at approximately 75K miles. I have photos on another device, if needed.

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.

Transmission shifting really hard, has problem shifting from low gear shaking when brakes are applied makes loud noises when you go reverse to park and park to any gear Driving home lost power Steering and had to pull of freeway This truck has already been in the dealer for 7 other warranty issues This will be the 4th issue with the transmission!!!! It has already been fixed once before on the transmission now again 2 Top Ends already now more transmission issues again We have been waiting for a new transmission for my 2018 sierra for over 3 months I have lost Complete faith that GMC really cares about the safety of people I have 2 LEMONS in my driveway just sitting The contact stated GM has not resolved the issue and there are no brakes which is a huge safety issue.

The warning light is saying engine power reduced having to do with the DEF system

“Engine power reduced” service message “Stabilitrack” service message “4x4” service message Vehicle is available for inspection Vehicle jerks and loses power while driving at highway speeds causing 18-wheelers and other drivers to swerve around me, vehicle accelerates very slowly while in city traffic. Intersections and traffic lights are difficult to navigate due to reduced engine power endangering myself and family, also other drivers. Vehicle erases all stored messages after a certain period of non-use. Dealer service center hasn’t reproduced symptoms. Service center technicians say nothing is wrong and releases the vehicle back to me. I have invoices of the vehicle taken in 3 times. Vehicle is currently in the service center as of 10 June 2023, for the same problems indicated above. Problem is unpredictable and occurs at random. Vehicle hasn’t been inspected by manufacturer, police or insurance representatives. Warning lamps, messages and symptoms started prior to September 23, 2022 can’t remember actual date. I have the first invoice vehicle was taken in to be serviced.

Backup lights are not working; bulbs are good. No apparent chafing/wear on wiring harness. Removed ground strap, cleaned and reattached. Still not working. 48,000 miles on 2018 GMC Canyon SLT, diesel engine.

I have been receiving the “Service Trailer Brake System” error intermittently. The only information I have been have to find around this is a defective wiring harnesses between two modules. This defect is not due to wear/tear and has been reported as a defective part on multiple GMC models. When this service error pops up it is distracting and very unsafe for driving as well as dangerous when towing as the driver has no idea of the trailer brake system is functioning properly..

Crash on 5/5 rear ended car - airbags did not deploy . Received concussion and neck injury.

I was on dirt forest road that was not a trail, I went through a ditch at about 3MPH and my side airbags blew. As a result the seatbelt pre tension device was also activated and the seat heaters no longer work.

Transmission shifting really hard, has problem shifting from low gear shaking when brakes are applied makes loud noises when you go reverse to park and park to any gear Driving home lost power Steering and had to pull of freeway This truck has already been in the dealer for 7 other warranty issues This will be the 4th issue with the transmission!!!! It has already been fixed once before on the transmission now again 2 Top Ends already now more transmission issues again We have been waiting for a new transmission for my 2018 sierra for over 3 months I have lost Complete faith that GMC really cares about the safety of people I have 2 LEMONS in my driveway just sitting The contact stated GM has not resolved the issue and there are no brakes which is a huge safety issue.

NO BRAKE FLUID HAD REPAIRED BY DEAL IN ONE WEEK SAME ISSUES NO BRAKE FLUID ONSTAR DIAGNOSTIC REPORT AND ALERTS SAY BRAKE SYSTEM ERROR NONENO ERROR CODE FOUNDNONE ABS - BRAKING AND STABILITY SYSTEMC0273AN ISSUE HAS BEEN DETECTED IN THE TRACTION CONTROL SYSTEM.SERVICE WITHIN 7 DAYS GOT THIS TODAY PULLED OVER NO FLUID DRIVING 30 MPH ON CITY STREET I HAVE ALL ONSTAR AND MECHANICS REPORT'S

The seat belts are very difficult to latch. It takes multiple attempts to get the seat belt locked in. I had a mechanic check and clean the buckle but it didn’t make an improvement and replacement was recommended. I have never had a seat belt buckle fail to easily latch. I am not the first owner and this issue has been ongoing.

I was on dirt forest road that was not a trail, I went through a ditch at about 3MPH and my side airbags blew. As a result the seatbelt pre tension device was also activated and the seat heaters no longer work.

Major potential for deadly fire or explosion. Fuel tank strapped failed after forward strap bolt fell out of threaded cross member where fastened in frame. The failure led to the fuel tank hanging inches off the ground on the freeway stressing fuel pump lines to forward upper tank. Metal grinding noises heard to prompt roadside inspection confirming hanging, unsecured tank full of 26gal of diesel. The tank wedged the fuel tank strap between plastic tank and drive shaft (propeller shaft) with heat and potentially spark as the the metal strap ground into the drive shaft marring and striating the durable metal. Heat and plastic melts, heat and spark with diesel combusts..in addition to risking of dragging tank at highway speed rupturing tank. Upon service at the dealer, mechanic observed the rear bolt to fuel strap was also loose and needed to be secured. GMC Protection Plan denied compensation for coverage as they do not cover "bolts, fuel straps, or manufacturer defects" under advertised "Bumper to Bumper" GMC Protection Plan marketed by GMC dealerships as protection for all non-wearable parts. No warning indicators appeared. My dog was in the truck bed in a camper shell directly above the potentially massive fire or explosion, this could have been catastrophic if it had been ignored. Additionally I was in northern California and southern Oregon when issue presented- potentially causing a major forest fire incident. While my outcome was fortunate in terms of safety, this could claim lives and even massive incidental loss of property. Vehicle has been inspected by local dealer and GM notified, hoping to receive coverage for damaged parts. Interestingly, there was previously a GM recall involving forward fuel strap dislodging and wearing into drive shaft on previous years of GM vehicles. No notable corrosion observed, bolts in question are high on frame secured to protected cross members, occurred at approximately 75K miles. I have photos on another device, if needed.

Transmission slipped almost from start. Took three appointments and two years - If my shop foreman knew the third time, why did he not call and tell me we now know your problem. I finally got fed up and brought it in one more time. Starter from day ONE maybe 50% of time made loud bang when Bendix retracted. Shop refused to take it off!!! I checked ball joint boots. One feels like no grease in it. They 'LOOKED' at it. No answer and nothing was done. Has had 'lifter noise' since new when small acceleration. Noise rate accelerates till shift and then repeats. I'm told they don't hear anything. I am 76 and hard of hearing. Pleeeeeze - don't tell me there isn't any. Not my best day today and felt it's time to say crap is crap.