Cert IV Auto Diagnostic study plan

Map the six-step diagnostic routine (verify complaint, gather information, analyse symptoms, test the most probable cause, repair, verify) and recite it from memory without notes

Practise selecting and justifying the correct scan tool data stream for five common driveability complaints

Interpret fuel trim, mass air flow, oxygen sensor and manifold pressure values against expected ranges and state what each deviation implies

Write a one-page decision tree that converts a lean-condition fuel trim pattern into three ranked candidate faults with a test for each

Demonstrate oscilloscope setup for a secondary ignition, injector and crankshaft position signal, stating time base, voltage scale and trigger choice

Perform and record a relative compression test and a cylinder balance test, then explain how the two results together narrow the fault

Apply vacuum and pressure gauge readings to distinguish intake restriction, exhaust restriction and mechanical timing faults

Construct a fault tree for a no-start condition that separates fuel, spark and compression paths with a measurable pass criterion at each branch

Diagnose mechanical timing faults by correlating camshaft and crankshaft signals and stating the acceptable correlation window

Test a charging circuit for voltage drop, ripple and parasitic draw, and state the pass threshold for each measurement

Trace an intermittent electrical fault through a wiring diagram, identifying connectors, grounds and splice points to probe in order

Explain how a networked module fault presents as a symptom in an unrelated system and how to confirm or exclude it

Interpret compression, leak-down and cylinder leakage results to classify the leak path as rings, intake valve, exhaust valve or head gasket

Diagnose driveline vibration by separating wheel-speed, engine-speed and driveshaft-speed related frequencies from road test observations

Test a transmission or driveline fault using stall, line pressure and shift timing data, and state what each result rules out

Explain how torque converter slip and lock-up behaviour appear in scan data and what values indicate a fault

Measure and interpret sensor reference voltage, signal return and ground offsets on a three-wire sensor circuit

Diagnose an anti-lock brake system fault from wheel speed sensor data, distinguishing sensor, wiring and tone ring causes

Test suspension and steering components for play, wear and alignment-related tyre wear patterns, and link each pattern to a likely cause

Verify a repair to an electronic chassis system by confirming fault code clearance, monitor readiness and a functional road test

Diagnose an air conditioning performance complaint using vent temperature, high and low side pressures, and ambient conditions, and state what each pressure pattern indicates

Explain refrigerant handling obligations including recovery, recycling, leak testing and record keeping for the refrigerant in use

Identify ten workshop hazards in a diagnostic bay and state the control measure for each, including high voltage and stored energy risks

Describe correct segregation, labelling and disposal of waste fluids, batteries and contaminated components

Write customer-facing explanations of three technical faults in plain language without jargon, each under 120 words

Produce a repair order that records complaint, cause, correction, parts, labour and verification in a form another technician could follow

Practise a verbal handover that states what was tested, what was found, what was ruled out and what remains uncertain

Apply a documented quality check to your own prior work, identifying at least three gaps in record completeness

Complete a timed 60-question mixed practice set covering all eight domains and record the score by domain

Re-study the two weakest domains using your own notes and re-test those domains until each reaches a stated pass mark

Recite the diagnostic routine, key measurement specifications and safety obligations from memory in a single review session

Review every flagged or uncertain item from earlier weeks and resolve each to a confirmed answer or an explicit knowledge gap