Within the first 1000 miles, this vehicle was noted to have a water leak on the passenger side of the vehicle, with water coming in under the dash. On bad rain days, as much as 1 - 1 1/2 gallon removed from floor pan. It took the dealer over a 1 1/2 years to find the leak and was tracked down to an improperly leaded roof seam over the passenger head above the windshield.
This water leak shorted out the electrical system several times, causing the Onstar system to be replaced x3, and loss of minutes due to the phone calling numbers repeatedly stored in the memory. I had to pull the wire connection on the back of the mirror and fuse several times to shut the system down.
This leakage also damaged the computer, and caused corrosion of the wire connections that have caused problems with the fan to the heating/cooling system, and failure of the keyless entry system.
Currently 01/09/09, I have additional electrical problems that have caused the fan, lights, and other electrical system to stay on after the vehicle is shut off, causing the battery to be dead in the morning. I am currently at the dealer, and after 3 hours the problem was tracked down to wire shorting in a wire bundle under the drivers side dash. The wires are unprotected and rub on a brake cylinder part in the firewall, causing a potential fire hazard. The wires in this bundle are melted together, and it's about a $600.00 fix that will not be covered by the factory. Even though, any reasonable person would not expect this to happen, and it's clearly a manufacturer's defect in equipment. Another works to expected reasonable wear.
I have also had a manifold crack at 40K, which cost me $1,000.00 to have repaired.
Now I have been informed by the dealer that GM is no longer going to make the Canyon - and it is probably for good reason.
This was the first GMC that I have ever purchased, and more than likely the last one. I originally purchased the vehicle because I wanted a high quality/value vehicle, and planned to keep the vehicle for some time; now I am just looking for a way to unload the thing.
One other thing.. 98% of my driving of this vehicle is express way. I have never had more that 15mpg with this vehicle, and that is at 70mph at over 104K.
Due to the wheel base and the wide tires on the vehicle, it tends to wander on roads with a lot of surface groves.
The vehicle is under powered with a 5 cyl, and shifts in and out of gears under load and on hills at highway speeds.
Safety Issue: Also, it should be noted that you should not use the cruse control in the Canyon on wet, snow covered roads, or going up hills, or on bridge overpass (low traction condition). If you lose speed the cruise will drop a gear and break traction with the back tire, causing you to spin out of control. This is almost impossible to recover from at expressway speed, and will cause an accident.
I have talked with several people who drive emergency vehicles, and this cruise control problem with the Canyon is a real danger. I was also informed that tires on the Canyon should be change before normal to prevent high speed traction loss with cruise control.