Unfortunately it is not covered by the powertrain warranty. The powertrain warranty covers internal parts in the engine and transmission, but doesnt cover components such as the alternator, starter, ac compressor, power steering pump, etc.
If you have an extended warranty, it may be covered by this, depending on level of coverage you bought.
Below are details of your powertrain warranty:
General Motors will warrant powertrains on 2008 and newer: Chevrolet, Buick, Pontiac, GMC and Saturn passenger cars, light duty trucks or vans for fully backed, 5 years or 100,000 miles, whichever comes first**. This warranty will have no deductible, starting from the original in-service date of the vehicle, for warrantable repairs which are required as a result of defects due to material and/or workmanship to the Powertrain components as listed below:
Cylinder head, block, timing gears, timing chain, timing cover, oil pump/oil pump housing, OHC carriers, valve covers, oil pan, seals, gaskets, turbocharger, supercharger and all internal lubricated parts as well as manifolds, flywheel, water pump, harmonic balancer and engine mount. Timing belts are covered until the first scheduled maintenance interval.
Case, all internal lubricated parts, torque converter, transfer case, transmission/transaxle mounts, seals, and gaskets.
Final drive housing, all internal lubricated parts, axle shafts, constant velocity joints, axle housing, propeller shafts, universal joints, wheel bearings, locking hubs, front differential actuator, supports, seals and gaskets.
During the warranty coverage period, alternate transportation and/or reimbursement of certain transportation expenses will be available under the Courtesy Transportation Program if your vehicle requires warranty repairs. Several transportation options are available. Refer to your Owners Manual for details, including reservation of rights, or consult your dealer/retailer.
General Motors is proud to offer the response, security, and convenience of the 24-hour Roadside Assistance Program for a period of 5 years or 100,000 miles/160,000 kms., whichever comes first. Refer to your Owner Manual for details, or consult your dealer/retailer. The Roadside Assistance contact information is listed in the Customer Assistance Offices section of the Warranty and Owner Assistance Information booklet.
All the above items are not covered for damage due to accident, misuse, alteration, insufficient or improper maintenance, contaminated or poor quality fuel. Medium Duty trucks, including the C4500, are excluded from this powertrain coverage. For complete details refer to your Warranty and Owner Assistance Information booklet.
This is a supplement to the express conditions and warranties described in the Warranty and Owner Assistance Information booklet. Other coverages are not extended or altered due to this supplement.