AUTONATOMY · ENGINE PERFORMANCE · UNIT 1 · LESSON 17

The Challenger: Engine Performance Diagnostic Capstone

Six customer complaints. Six different faults. Read the symptoms, select tests, compare independent evidence, and explain your diagnosis. The objective is not to guess a part—it is to find what the measurements do and do not prove.

Your mission

Choose a service bay below. Each bay begins with a customer concern and a limited scan-tool snapshot. Order diagnostic tests, then submit your fault hypothesis. Your case is marked complete only when the diagnosis is supported by the relevant confirming evidence.

Training simulation—not OEM data. All vehicles, numeric readings, trouble-code examples, and test outcomes are invented for teaching. Test selections represent properly performed, approved procedures—not instructions to swap live high-voltage ignition components or operate unsafe vehicles. For real repairs, verify equipment setup, applicable safety requirements, and manufacturer-specific service information.

Diagnostic mission board

Select a case; passed cases remain marked while you explore others.

Cases completed0 / 6
Current tests0
MasteryIn progress
BAY 1 · UNKNOWN CAUSE

Customer concern

Initial scan-tool / road-test information

This snapshot narrows the possibilities; it does not establish the root cause.

1 · Choose diagnostic tests

Order tests that discriminate between different causes. Results appear in the evidence notebook; repeating a completed test is unnecessary.

No tests ordered yet. What could disprove your first hypothesis?

2 · Evidence notebook

Awaiting test results
  1. Select a test to collect your first piece of evidence.

3 · Commit to a hypothesis

Finishing a case does not authorize a real repair. Vehicle-specific confirmation is still required.

Unit 1 · Concept map

Link each symptom to the system that can explain it: air (MAF/MAP, throttle, boost, intake leaks), fuel (pressure, pulse width, injectors, trims), spark and synchronization (ignition, CKP/CMP), mechanics (compression, leakage, VVT), and emissions (oxygen sensors, catalyst, EVAP, EGR, PCV). A data point may be consistent with several faults. Seek the measurement that distinguishes them.

Hands-on bridge: For an instructor-led assessment, transfer a case to an actual training vehicle, supply verified OEM specifications, have students document test setup and readings, and assess safe tool operation separately from written diagnostic reasoning.