Fuel, Ignition and Emission Systems
How a gasoline engine's fuel, ignition and emission control systems work and how they are diagnosed and repaired, followed through an apprentice's spring at Ridgeline Auto Service in Denver: combustion and the air-fuel ratio, fuel delivery, port and direct injection, the sensors used for fuel control, fuel trims and closed-loop control, ignition systems, coils and spark plugs, evaporative emission systems, catalysts, EGR and particulate filters, OBD-II monitors and trouble codes, EPA rules, the Colorado emissions inspection program and why tampering is never an option, and a capstone diagnosis of a check-engine light from code to verified repair.
AUTO-230 12 lessons · 4 h 2 min ▶ Video lessons coming soon
Offered by HSM University · Automotive Service
This is the American version of this course. See the Canadian version.
What you'll learn
- Explain gasoline combustion, the stoichiometric air-fuel ratio and lambda, and how HC, CO, NOx and particulates form, and interpret exhaust gas readings
- Explain how fuel is stored and delivered in return, returnless and direct-injection systems, and test fuel pressure, volume and pump current safely
- Compare port and direct fuel injection, explain how pulse width is calculated, and test, service and replace injectors
- Explain how MAF, MAP, temperature, throttle, pedal, crankshaft, camshaft, knock and exhaust oxygen sensors work, and judge their readings, including the effect of altitude
- Interpret short-term, long-term and total fuel trims by bank and operating condition, and use the pattern to locate lean and rich faults
- Explain how ignition coils, dwell and spark timing work in distributor, waste-spark and coil-on-plug systems, and test coils and their circuits
- Inspect, read and replace spark plugs, explain misfire detection, and diagnose misfires by separating ignition, fuel and mechanical causes
- Explain how the evaporative emission system stores and purges fuel vapor and tests itself for leaks, and locate EVAP faults with scan tool tests and smoke testing
- Explain how catalytic converters, EGR, secondary air and particulate filters reduce emissions, diagnose catalyst efficiency codes, and select legal replacement parts
- Explain OBD-II monitors, pending, confirmed and permanent codes, freeze frame, readiness and Mode 6 data, and decode trouble codes
- Explain EPA standards, the emissions warranty, state inspection programs such as Colorado's and the Clean Air Act's tampering rules, and prepare vehicles to pass an OBD inspection
- Diagnose a check-engine light from interview to verified repair, and document the complaint, cause and correction on a repair order
Course content
12 lessons · 4 h 2 min total · final exam
- 1 Combustion, air-fuel ratio and emissions 22 min · quiz
- 2 Fuel delivery: tanks, pumps and lines 20 min · quiz
- 3 Port and direct fuel injection 20 min · quiz
- 4 Engine sensors for fuel control 20 min · quiz
- 5 Fuel trims and closed-loop control 20 min · quiz
- 6 Ignition systems and coils 20 min · quiz
- 7 Spark plugs and ignition diagnosis 19 min · quiz
- 8 Evaporative emission systems 19 min · quiz
- 9 Exhaust aftertreatment: catalysts, EGR and particulate filters 22 min · quiz
- 10 OBD-II monitors and diagnostic trouble codes 20 min · quiz
- 11 EPA and state emissions inspections 19 min · quiz
- 12 Capstone: diagnosing a check-engine light from code to repair 21 min · quiz
- E Final exam 20 questions
Requirements
Recommended background. You can start any course at any time.
Description
How a gasoline engine's fuel, ignition and emission control systems work and how they are diagnosed and repaired, followed through an apprentice's spring at Ridgeline Auto Service in Denver: combustion and the air-fuel ratio, fuel delivery, port and direct injection, the sensors used for fuel control, fuel trims and closed-loop control, ignition systems, coils and spark plugs, evaporative emission systems, catalysts, EGR and particulate filters, OBD-II monitors and trouble codes, EPA rules, the Colorado emissions inspection program and why tampering is never an option, and a capstone diagnosis of a check-engine light from code to verified repair.