Check Engine Light Master Course

01 CE01 - Check Engine Light Diagnostic Mindset and Workflow

• CE01-L01 – What the Check Engine Light Actually Means
• CE01-L02 – Complaint Verification, Warning Lamp Status, and First Scan
• CE01-L03 – MIL On, MIL Flashing, Pending Codes, History Codes, and No-Code Complaints

02 CE02 - OBD-II Foundations, Monitors, and Scan Tool Basics

• CE02-L01 – OBD-II Purpose, Generic vs Enhanced Data, and Connector Basics
• CE02-L02 – Readiness Monitors, Drive Cycles, and Inspection Logic
• CE02-L03 – Freeze Frame, Mode $06, Permanent Codes, and Clear-Code Consequences

03 CE03 - DTC Strategy: P0/P1 Codes, Pending, Confirmed, Permanent

• CE03-L01 – How Diagnostic Trouble Codes Are Set and Confirmed
• CE03-L02 – Generic P0 Codes vs Manufacturer P1 Codes and Enhanced Modules
• CE03-L03 – Code Priority, Symptom Priority, and Avoiding Parts Cannon Mistakes

04 CE04 - Fuel Trim, Oxygen Sensors, and Lean/Rich Codes

• CE04-L01 – STFT, LTFT, Total Trim, and Pattern Interpretation
• CE04-L02 – P0171/P0174 Lean Codes and P0172/P0175 Rich Codes
• CE04-L03 – Oxygen Sensor and AFR Sensor Codes Without False Sensor Blame

05 CE05 - Misfire Codes, Flashing MIL, and Catalyst Protection

• CE05-L01 – P0300 Random Misfire and Cylinder-Specific Misfire Logic
• CE05-L02 – Ignition, Fuel, Compression, Vacuum, and Mechanical Misfire Separation
• CE05-L03 – Flashing Check Engine Light, Catalyst Damage Risk, and Stop-Drive Rules

06 CE06 - EVAP Codes and Fuel Vapor System Diagnostics

• CE06-L01 – EVAP System Purpose, Purge, Vent, Canister, and Leak Detection
• CE06-L02 – P0440, P0442, P0455, P0456, and Gas Cap Myths
• CE06-L03 – Smoke Testing, Purge Valve Testing, and EVAP Monitor Validation

07 CE07 - Catalyst, Exhaust, and Efficiency Codes

• CE07-L01 – Catalyst Efficiency, Upstream/Downstream O2 Logic, and P0420/P0430
• CE07-L02 – Exhaust Leaks, Fuel Control, Misfire, and False Catalyst Codes
• CE07-L03 – Catalyst Verification, Temperature, Backpressure, and Legal Boundaries

08 CE08 - MAF, MAP, Throttle, and Air Measurement Codes

• CE08-L01 – MAF Sensor Codes, Contamination, Grams per Second, and Load Logic
• CE08-L02 – MAP Sensor, Baro, Vacuum, Load, and Speed Density Diagnosis
• CE08-L03 – Electronic Throttle Body, APP/TPS Plausibility, Limp Mode, and Relearn

09 CE09 - EGR, PCV, Intake Leaks, and Idle Control Codes

• CE09-L01 – EGR Flow Codes, Stuck Open/Closed Patterns, and Driveability Symptoms
• CE09-L02 – PCV Faults, Vacuum Leaks, Unmetered Air, and Idle Codes
• CE09-L03 – Idle Control, Stalling, Rough Idle, and No-Code CEL-Adjacent Complaints

10 CE10 - Cooling System, Thermostat, Temperature, and Overheat Codes

• CE10-L01 – ECT Sensor, Thermostat Rationality, P0128, and Warm-Up Logic
• CE10-L02 – Cooling Fan Codes, Overheat Warnings, and Temperature Plausibility
• CE10-L03 – Temperature-Related Fuel, Emissions, and Readiness Effects

11 CE11 - Transmission, ABS, SRS, and Network Warning Interactions

• CE11-L01 – Why Check Engine, Traction, ABS, and Transmission Lights Appear Together
• CE11-L02 – CAN Network U-Codes, Module Communication, and Shared Sensor Data
• CE11-L03 – When CEL Diagnosis Requires Enhanced Scan Tool or Specialist Escalation

12 CE12 - Live Data Graphing and Evidence Capture

• CE12-L01 – Choosing the Right PIDs for Each CEL Complaint
• CE12-L02 – Graphing Fuel Trim, O2, MAF, MAP, RPM, Load, and Temperature Together
• CE12-L03 – Data Logging, Road Testing, Intermittent CEL Capture, and Evidence Review

13 CE13 - Readiness, Emissions Inspection, and Drive Cycle Strategy

• CE13-L01 – Readiness Not Complete, Monitor Preconditions, and Drive Cycle Planning
• CE13-L02 – Permanent Codes, Failed Inspection, and Clear-Code Mistakes
• CE13-L03 – Emission Repair Verification and Monitor Completion Without Cheating

14 CE14 - Electrical, Power, Ground, and Sensor Reference Problems

• CE14-L01 – 5V Reference Shorts, Sensor Pull-Down, and Multiple Unrelated Codes
• CE14-L02 – Ground Faults, Charging Voltage, Low Voltage Codes, and Module Confusion
• CE14-L03 – Connector Pin Fit, Water Intrusion, Harness Rub, and Intermittent CEL

15 CE15 - Diesel Check Engine Light and DPF/SCR/NOx Codes

• CE15-L01 – Diesel CEL Basics: DPF, EGR, Boost, Fuel, Glow, and Sensor Strategy
• CE15-L02 – DPF Regeneration, Differential Pressure, Soot Load, and Stop-Drive Rules
• CE15-L03 – SCR, DEF, NOx Sensors, AdBlue Warnings, and Legal Boundaries

16 CE16 - Hybrid/EV Check Engine and 12V/High-Voltage Boundaries

• CE16-L01 – Hybrid CEL, Ready Mode, Engine Start/Stop, and 12V Influence
• CE16-L02 – Hybrid Battery, Inverter, DC/DC, Isolation, and Safety Boundaries
• CE16-L03 – When to Stop and Escalate Hybrid/EV CEL Work

17 CE17 - Case Studies: Common CEL Patterns

• CE17-L01 – Lean Code Case Study: Vacuum Leak, MAF, Fuel Pressure, or O2?
• CE17-L02 – Misfire Case Study: Coil, Injector, Compression, or Vacuum?
• CE17-L03 – EVAP and P0420 Case Study: Cheap Guess vs Evidence-Based Repair

18 CE18 - Repair Decisions, Verification, Reports, and Customer Communication

• CE18-L01 – Clean, Test, Repair, Replace, Relearn, or Escalate Decision Logic
• CE18-L02 – Post-Repair Verification, Monitor Check, Road Test, and Final Scan
• CE18-L03 – Customer Report, Risk Disclosure, Estimate Language, and Maintenance Advice

19 CE19 - Capstone Check Engine Light Diagnostic Workflow

• CE19-L01 – Building the Complete CEL Diagnostic Tree
• CE19-L02 – Timed Workshop Simulation: First 30 Minutes of a CEL Vehicle
• CE19-L03 – Final Capstone Case: Scan, Interpret, Test, Repair, Verify, and Release

20 CAPSTONE - Integrated Check Engine Light Diagnostic Cases and Professional Release

• Capstone Final Assessment and Professional Release Logic