General Motors Corporation (GMC) is a division of General Motors, Inc. that manufactures a variety of pickups, vans, and sport utility vehicles. As of 2010, GMC is manufacturing three pickup lines: the Sierra, the Sierra Heavy Duty, and the Canyon, though they also have some retired pickup lines. Just as with other pickups, the GMC pickups might require troubleshooting on occasion because of problems starting. There are a few checks you can make before calling a professional.
Try to start the engine by placing the key into the ignition switch of your GMC pickup and turning it. If the key does not turn at all, the steering column might not be locked. Turn the steering wheel left and then right. You should hear a click when it is locked. Turn the key again.
Turn the key to the "Accessories" mode. Look at the fuel gauge. If the fuel is low or empty, the vehicle will not start properly. If this is the case or you are unsure of whether the gauge is accurate, add a gallon of the appropriate fuel to the fuel tank. Try to start your GMC pickup again.
Complete a simple diagnostic check on the battery. With the key in "Accessories" mode, turn off the interior lights or headlights. Look to see if the lights are lit up. If they are not turning on in "Accessories" mode, the battery is likely the problem. The battery of your pickup might need to be jump-started, charged, or even replaced.
Check the fluid levels. Read your owner's manual to locate the transmission fluid, coolant and oil dipsticks. Pull the lever, and open the hood. Check the levels of each fluid, making sure each is filled to the appropriate level. If fluids are too low or empty, the engine could be damaged or have trouble starting.
Listen for any sounds that might indicate what the problem is when attempting to start the vehicle. If your pickup starts briefly but then shuts off, there might be a problem with the fueling system. Clicking noises can mean your starter needs to be replaced, and no sound can mean your ignition switch needs to be replaced.
Tow your GMC pickup or have it towed to a garage or dealership that will be able to perform more extensive diagnostic testing and repairs. Contact a GMC dealership with questions about the specific mechanics of a GMC pickup.
