ITI Mechanic Auto Electrical & Electronics (AITT Theory) study guide
ITI Mechanic Auto Electrical & Electronics (AITT Theory) · Work through your exam, one topic at a time.
The ITI Mechanic Auto Electrical & Electronics trade theory paper, assessed under the AITT (All India Trade Test) scheme for NCVT-affiliated ITIs, is the written theory component of the trade certification for students training to work on vehicle electrical and electronic systems. It suits apprentices and ITI trainees who want a recognised trade qualification before working in automotive service workshops, OEM dealer service centres, fleet maintenance depots, or as self-employed auto electricians. The ITI Mechanic Auto Electrical & Electronics (AITT Theory) study guide has 12 sections and about 3,755 words.
01Trade Safety, Tools, Measuring Instruments and Workshop Practice
This domain checks whether you can work on vehicle electrical systems without injuring yourself or damaging test equipment. Expect questions on battery handling, insulated tools, multimeter connections, torque and workshop control.
348 words, about 2 min02Basic Electricity, Magnetism and Electrical Units
Ohm's law, series and parallel circuits, power, magnetism and SI units applied to vehicle circuits. V = I × R; P = V × I = I²R = V²/R.
318 words, about 2 min03Batteries
Lead-acid construction, ratings, state of charge, testing, charging and safety. A 12 V battery has six cells at about 2.1 V each.
326 words, about 2 min04Charging Systems and Starting Systems
Alternator, regulator, starter, cranking circuit and voltage-drop diagnosis. Alternator: rotor field, three-phase stator, six-diode rectifier, integrated regulator.
296 words, about 1 min05Wiring, Cables, Connectors, Fuses and Circuit Protection
Cable sizing, terminals, fuses, relays, grounds and circuit protection. Cable must carry the load current with acceptable voltage drop.
312 words, about 2 min06Ignition Systems and Engine Management Sensors/Actuators
Coil operation, spark timing, sensor signal types and actuator testing. Ignition coils store energy in the primary; opening the primary circuit collapses the field and induces high voltage in the secondary.
306 words, about 2 min07Lighting, Horn, Wiper, Indicators and Body Electrical Accessories
Lamp circuits, switches, flashers, wiper systems, horns and body accessories. Halogen bulbs need correct wattage and clean glass; HID lamps use a ballast that generates high voltage at start-up; LED lamps are polarity-sensitive and draw low current.
337 words, about 2 min08Electronic Components, Semiconductors and Basic Electronic Circuits
Passive components, diodes, transistors, simple circuits and safe handling. Resistor colour code: black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, grey 8, white 9.
288 words, about 1 min09Electronic Control Units
ECU architecture, inputs and outputs, power supplies, memory and replacement procedures. An ECU contains a microprocessor, ROM/flash for programs, RAM for temporary data, EEPROM for adaptive and immobiliser data, an A/D converter, and output drivers.
298 words, about 1 min10Multiplexing/CAN Bus and Vehicle Networks
Vehicle network types, CAN voltage levels, termination and network diagnosis. CAN is a differential bus on twisted pair.
301 words, about 2 min11Diagnostic Equipment, Fault Finding and Testing Procedures
A structured diagnostic process, scan tool use, scope and meter testing, and verification. Verify the complaint, gather symptoms and conditions, check for technical bulletins, then read DTCs and freeze-frame data before clearing anything.
305 words, about 2 min12Hybrid and Electric Vehicle Electrical Systems and High-Voltage Safety
High-voltage system layout, safety procedures, isolation testing and 12 V interaction. Traction batteries commonly operate at 300–400 V DC, with some systems at 800 V.
320 words, about 2 min