GM Service Manual Online
For 1990-2009 cars only

Strategy Based Diagnostics

Review the system operations in order to familiarize yourself with the system functions. Refer to Driveline Disassembled Views and Driveline Support Assembly Description . All diagnosis on a vehicle should follow a logical process. Strategy based diagnostics is a uniform approach for repairing all systems. The diagnostic flow should always be used in order to resolve a system condition. The diagnostic flow is the place to start when repairs are necessary. For a detailed explanation, refer to Strategy Based Diagnosis .

Visual/Physical Inspection

    • Inspect for aftermarket devices, which could affect the operation of the vehicle. Refer to Checking Aftermarket Accessories .
    • Inspect the easily accessible or visible system components for obvious damage or conditions, which could cause the symptom.
    • Verify the exact operating conditions under which the concern exists. Note factors such as vehicle speed, road conditions, ambient temperature, and other specifics.
    • Compare driving characteristics or sounds, if applicable, to a known good vehicle and make sure you are not trying to correct a normal condition.

Intermittent

Text the vehicle under the same conditions that the customer reported in order to verify the system is operating properly.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

    •  Diagnostic Starting Point - Vibration Diagnosis and Correction
    •  Wheel Drive Shafts Description and Operation
    •  Diagnostic Starting Point - Wheel Drive Shafts
    •  Diagnostic Starting Point - Rear Drive Axle
    •  Rattle Noise
    •  Scraping Noise
    •  Moaning Noise
    •  Whirring or Squealing Noise
    •  Squeak Noise
    •  Knock or Clunk Noise
    •  Shudder on Acceleration at Low Speed