Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Engine Controls - Introduction - CNG, Flex-Fuel & Gasoline: Preface: Notes
This article provides a step-by-step approach for diagnosing driveability, emission and powertrain control system symptoms. Before beginning diagnosis, it may be helpful to reference any Technical Service Bulletins (TSBs) information when this is available.
This article is used in conjunction with the Body, Chassis, Electrical, Powertrain articles, and the Wiring Diagram articles. Additional articles are used to provide additional diagnostics when directed by this article. Additional articles are also used for component removal and replacement information. Refer to the Wiring Diagram articles for vehicle specific wiring information and component, connector and splice location.
The following is a description of the information contained in each of the ENGINE PERFORMANCE articles.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.