GM Service Manual Online
For 1990-2009 cars only

Comparing the customer's vehicle to a KNOWN GOOD vehicle that is essentially identical will help determine if the customer's concern may be characteristic of a vehicle design. To arrive at a valid conclusion, the comparison must be performed under the same conditions, using the same criteria, on a vehicle that has the same option content as the customer's vehicle.

The comparison vehicle must match the customer's vehicle in the following areas:

    • Year
    • Make
    • Model
    • Body style
    • Powertrain configuration
    • Driveline configuration
    • Final drive ratio
    • Tire/wheel size and type
    • Suspension package
    • Trailering package
    • GVW rating
    • Performance options
    • Luxury options