MITO Light Auto L5 flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

M1 vehicle category

EU classification for passenger vehicles with no more than eight seats in addition to the driver's seat, covering typical passenger cars and light MPVs used in MITO Light Auto scope.

Gross vehicle mass

The maximum permissible total mass of a vehicle including kerb mass, payload, and driver allowance, as declared by the manufacturer and enforced at inspection.

Kerb mass definition

Mass of the vehicle with all fluids, tools, and 90% fuel but without driver, passengers, or cargo; used to compute payload by subtracting from gross vehicle mass.

Monocoque construction

Unitary body structure where the body panels and sills form the load-bearing chassis, improving crash energy management and reducing mass compared with ladder-frame designs.

N1 vehicle category

EU classification for goods vehicles with a maximum gross mass not exceeding 3.5 tonnes, covering light vans and light trucks commonly serviced in light-auto workshops.

Four-stroke cycle

Engine cycle comprising intake, compression, power, and exhaust strokes, requiring two crankshaft revolutions (720 degrees) to complete one full cycle per cylinder.

Engine displacement formula

Total swept volume calculated as (pi divided by 4) times bore squared times stroke times the number of cylinders, expressed in cubic centimetres or litres.

Compression ratio

Ratio of the cylinder volume at bottom dead centre to the volume at top dead centre; petrol engines typically 9:1 to 12:1, diesel engines 17:1 to 22:1.

Stoichiometric air-fuel ratio

The mass ratio of air to fuel at which complete combustion occurs; approximately 14.7:1 for petrol and 14.5:1 for diesel, used to define lambda equal to one.

Lambda value

Ratio of actual air-fuel ratio to the stoichiometric ratio; lambda above one indicates lean mixture, below one indicates rich, and one indicates stoichiometric combustion.

Power from torque formula

Engine power in kilowatts equals torque in newton-metres multiplied by engine speed in rpm, divided by 9549, allowing conversion between torque and power curves.

Common rail injection

Diesel fuel system where a high-pressure pump pressurizes a shared rail and the ECU commands individual injectors for pilot, main, and post injection events.

Ohm's law

Relationship stating voltage equals current multiplied by resistance; used to calculate expected current draw or voltage drop across a circuit component during diagnosis.

Electrical power formula

Power in watts equals voltage multiplied by current, and equivalently current squared times resistance or voltage squared divided by resistance.

Battery open-circuit voltage

A fully charged 12 V lead-acid battery reads approximately 12.6 V at rest; 12.0 V indicates roughly 50 percent state of charge and requires charging.

Voltage drop test

Measurement of voltage lost across a circuit while current flows; total drop above about 0.5 V in a starter circuit indicates excessive resistance at connections or cables.

CAN bus termination

Controller area network requires two 120 ohm terminating resistors giving about 60 ohms measured across CAN-H and CAN-L, preventing signal reflections on the bus.

High-voltage safety threshold

Systems operating above 60 V DC or 30 V AC are classified as hazardous high voltage, requiring qualified technicians, insulated tools, and verified de-energization before service.

Camber angle

Wheel alignment angle describing the vertical tilt of the wheel relative to the vehicle; negative camber tilts the top inward and affects cornering grip and tyre wear.

Caster angle

Alignment angle formed by the steering axis tilt from vertical; positive caster improves straight-line stability and steering self-centering after a turn.

Thrust angle

Angle between the vehicle's geometric centreline and the rear axle centreline; incorrect thrust angle causes off-centre steering and uneven tyre wear.

Tyre load index

Numerical code on the tyre sidewall indicating maximum load capacity per tyre at specified inflation pressure; must meet or exceed the vehicle manufacturer requirement.

Brake fluid boiling point

DOT 4 fluid has a minimum dry boiling point of 230 degrees Celsius; absorbed moisture lowers this value and can cause vapour lock under heavy braking.

ABS wheel-speed sensor

Sensor monitoring wheel rotation and reporting to the ABS control unit; a fault disables anti-lock function and illuminates the warning lamp on the dashboard.

Ackermann steering principle

Geometry where the inner front wheel turns through a larger angle than the outer wheel so both wheels follow concentric arcs without tyre scrub during cornering.

OBD-II diagnostic link

Standardized 16-pin connector under the dashboard, with CAN communication on pins 6 and 14, used to read emission-related codes and readiness monitor status.

Diagnostic trouble code structure

Code format starting with a letter for system (P powertrain, B body, C chassis, U network) followed by digits indicating generic or manufacturer-specific origin.

Readiness monitors

OBD-II self-tests for misfire, fuel system, catalyst, EVAP, oxygen sensor, and EGR that must complete before an emissions test can be passed.

Tyre tread minimum depth

Legal minimum tread depth of 1.6 millimetres in the European Union; replacement is recommended at approximately 3 millimetres for wet grip performance.

Torque-to-yield bolt

Fastener tightened beyond its elastic limit during assembly; it must be replaced rather than reused because its clamping force is no longer predictable.

Three-way catalyst function

Emission device converting carbon monoxide, hydrocarbons, and nitrogen oxides into carbon dioxide, water, and nitrogen when the engine operates near stoichiometric air-fuel ratio.

AdBlue and SCR system

Selective catalytic reduction system injecting urea solution into diesel exhaust to convert nitrogen oxides into nitrogen and water, requiring periodic AdBlue refilling.