Making Sense of European Fuel Trim

This course, “Making Sense of European Fuel Trim,” will assist the technician with knowledge of domestic fuel trim diagnostics to expand his capabilities into applying those skills to European manufactured vehicles. The course will discuss new terms such as additive and multiplicative fuel trim and understand the different ways European cars display data as opposed to their domestic counterparts.

AVI instructor Jim Wilson will explain basic European fuel trim systems, diagnostic procedures, and give specific OEM examples of reading, logically diagnosing, and correcting short and long-term fuel trim issues.

Objectives
After this session, the student will be able to:

• State why checking the oxygen sensor first is important
• Differentiate between multiplicative and additive fuel trim
• Understand when to determine fuel trim from the OBD2 side or the OEM side
• Explain multiple long term fuel trim readings and when they need to be examined
• Describe how fuel trim differs from each OEM
• Understand the different types of enhanced scan tools and how they differ
• List the importance of accurate data from the catalytic converter
• State the different terminology used in European fuel trim as compared to domestic terms
• Differentiate between closed-loop and open-loop fuel systems
• Explain “logical” fuel trim diagnostics
• Understand the importance of vehicle load on fuel trim diagnostics
• Be able to interpret scan tool data and the applicable DTCs
• Explain the importance of OEM Technical Service Bulletins