ASE F1 Compressed Natural Gas Vehicles study plan

Define the properties of natural gas (methane content, flammability range, specific gravity, octane rating) and explain how each property drives CNG vehicle design and safety practice

Identify the major codes and standards that govern CNG vehicle fuel systems and state what each one covers

Label the components of a complete CNG fuel system on a hand-drawn schematic, from receptacle to injector

Describe cylinder classifications and labeling/marking requirements, and explain how to read a cylinder label to determine its service life and inspection status

Explain the function and failure modes of the manual shutoff valve, check valve, solenoid valve, and pressure relief device on a CNG cylinder

Distinguish the types of pressure relief devices and describe the conditions that activate each

Outline the required cylinder inspection intervals and the criteria that condemn a cylinder from service

Demonstrate the safe cylinder isolation and venting sequence in the correct order without reference notes

Identify high-pressure line, fitting, and tubing types used in CNG service and state the pressure rating requirements for each

Explain proper fitting installation and torque practice, and describe how to detect an improperly made connection

Describe the inspection points along a high-pressure line run and the damage types that require component replacement rather than repair

Sequence the depressurization and safe removal procedure for a high-pressure line segment

Trace the pressure reduction path from tank pressure to injector supply pressure and explain the role of each regulator stage

Diagnose common regulator faults (creep, icing, low outlet pressure) from described symptoms

Explain how the engine control system determines fuel mass for CNG and how that differs from liquid fuel metering

Describe injector types used in CNG service and the symptoms of injector wear or clogging

Explain how air/fuel ratio targets and closed-loop fuel trim behave on a CNG engine and interpret fuel trim data

Identify the sensors that feed the CNG fuel control strategy and describe the effect of a failed sensor on driveability

Compare ignition system requirements for CNG (higher voltage demand, plug gap and heat range, coil stress) with gasoline

Diagnose a misfire on a CNG engine by separating ignition causes from fuel metering causes

Describe receptacle types, inspection criteria, and the correct fueling and defueling procedures including safety precautions

Explain leak detection methods for CNG and the response procedure for a detected leak

Build a preventive maintenance schedule for a CNG vehicle covering inspection intervals and wear items

Apply a structured diagnostic process to a no-start or low-power CNG complaint using pressure, leak, and control data

Perform a full-system inspection sequence from receptacle to cylinder and document findings in a standard format

Explain the regulatory and safety obligations that apply to a technician servicing CNG vehicles, including venting and confined-space practice

Identify the top failure points across the system and rank them by safety consequence

Resolve weak areas flagged in earlier weeks by re-testing on missed objectives

Complete timed practice sets across all eight domains and score each domain separately

Re-study any domain scoring below 80% until recall is solid

Recite the safety-critical procedures (isolation, venting, leak response, defueling) without notes

Confirm readiness by reviewing the weakest two domains one final time