Important Preliminary Inspections Before Starting

WARNING: This page is about a different car, the 2008 Buick LaCrosse and 2008 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.

Before using the Symptom diagnosis, perform the following:

Perform Diagnostic System Check - Vehicle and verify all of the following items:
- Ensure that the engine control module (ECM) or powertrain control module (PCM) and indicator lamp are operating correctly.
- Ensure that there are no diagnostic trouble codes (DTCs) that are stored.
- Scan tool data is within a normal operating range.
Verify the customer concern.
Perform the Visual/Physical Inspection in this section. The visual/physical inspection is extremely important, and can lead to correcting a condition without additional testing. It may also help reveal the cause of an intermittent condition.
Locate the correct symptom. Perform the tests and inspections associated with the symptom.

Review the system operation in order to familiarize yourself with the system functions.