Episode 175
Fuel Trims [E175]
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Contact Information
Introduction:
- Fuel trims are a common topic in professional forums, classes, and diagnostics, often leading to bold diagnostic decisions.
- Matt shares his experience of quickly diagnosing vehicle issues using fuel trims, even before leaving the parking lot.
Key Challenges in Discussing Fuel Trims:
- The more you learn about fuel trims, the more nuanced and complex the topic becomes.
- It’s difficult to generalize fuel trim behavior across all vehicles, as each system has unique characteristics.
- Fuel trims are just one piece of data that must be factored into a broader diagnostic process.
What Are Fuel Trims?
- Definition: Fuel trims are adjustments made to the base fuel schedule by the engine control unit (ECU).
- Matt credits Matt Ragsdale on iATN for one of the best explanations he’s seen.
Two Primary Fuel Systems:
- Speed Density Systems:
- Relies on the Manifold Absolute Pressure (MAP) sensor and engine RPM as primary inputs.
- Engine control algorithms tend to be more complex.
- Mass Airflow (MAF) Systems:
- Uses the Mass Airflow Sensor (MAF) and crank sensor (RPM) as primary inputs.
- Simpler in design compared to speed density systems.
- Modern systems often blend elements of both speed density and MAF systems.
Closing Thoughts:
- Matt emphasizes the importance of understanding the nuances of fuel trims and how they vary across different vehicle systems.
- He plans to dive deeper into the topic in future episodes, providing more detailed insights and practical examples.
The Aftermarket Radio Network: https://aftermarketradionetwork.com/
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Diagnosing the Aftermarket A to Z with Matt Fanslow: From Diagnostics to Metallica and Mental Health, Matt Fanslow is Lifting the Hood on Life. https://mattfanslow.captivate.fm/
Business by the Numbers with Hunt Demarest: Understand the Numbers of Your Business with CPA Hunt Demarest. https://huntdemarest.captivate.fm/
The Auto Repair Marketing Podcast with Kim and Brian Walker: Marketing Experts Brian & Kim Walker Work with Shop Owners to Take it to the Next Level. https://autorepairmarketing.captivate.fm/
The Weekly Blitz with Chris Cotton: Weekly Inspiration with Business Coach Chris Cotton from AutoFix - Auto Shop Coaching. https://chriscotton.captivate.fm/
Speak Up! Effective Communication with Craig O'Neill: Develop Interpersonal and Professional Communication Skills when Speaking to Audiences of Any Size. https://craigoneill.captivate.fm/
Remarkable Results Radio Podcast with Carm Capriotto: Advancing the Aftermarket by Facilitating Wisdom Through Story Telling and Open Discussion
Diagnosing the Aftermarket A to Z with Matt Fanslow: From Diagnostics to Metallica and Mental Health, Matt Fanslow is Lifting the Hood on Life.
The Auto Repair Marketing Podcast with Kim and Brian Walker: Marketing Experts Brian & Kim Walker Work with Shop Owners to Take it to the Next Level.
The Weekly Blitz with Chris Cotton: Weekly Inspiration with Business Coach Chris Cotton from AutoFix - Auto Shop Coaching.
Business by the Numbers with Hunt Demarest: Understand the Numbers of Your Business with CPA Hunt Demarest.
Speak Up! Effective Communication with Craig O'Neill: Develop Interpersonal and Professional Communication Skills when Speaking to Audiences of Any Size.
