NVQ L4 Automobile Technician key terms

A documented process that identifies hazards in a workshop task, judges how likely and how severe the harm could be, and records the controls needed before work starts.

The ranked order of ways to reduce risk: eliminate the hazard, substitute it, engineer it out, change working practice, then rely on personal protective equipment as the last resort.

A written evaluation of substances hazardous to health used in the workshop, covering exposure routes, safe handling, storage, spill response and the protective measures required.

A supplier document listing a product's hazards, first-aid measures, handling and storage advice, and disposal requirements, used to inform the workshop's substance assessment.

A step-by-step description of how a high-risk task will be carried out safely, naming the sequence of operations, the people responsible and the controls at each stage.

A formal written authorisation required before certain hazardous tasks, confirming that isolation, gas testing or fire precautions are in place and that a named person has authorised the start.

A procedure for isolating an energy source, applying a personal lock and warning tag, and proving the system dead so machinery or a vehicle cannot be re-energised during repair.

An evaluation of a lifting or carrying task against load weight, posture, distance and repetition, used to decide whether mechanical aids or a two-person lift is needed.

The regulations controlling dangerous substances and explosive atmospheres, which govern how flammable solvents, fuel vapours and dusts are stored, used and ventilated in the workshop.

A raised lip or sealed tray around a fluid container or tank that holds the contents if it leaks, preventing fuel, oil or coolant reaching drains or bare ground.

A planned order of checks, from confirming the complaint through to verifying the repair, that avoids random part replacement and is based on how the system actually works.

The step of translating a customer's description of a fault into the specific system, circuit or component most likely responsible, using knowledge of how those parts interact.

A structured investigation that keeps asking why a failure occurred until the underlying cause, rather than the visible damage, is identified and can be corrected.

A simple technique of asking why repeatedly, usually about five times, to move from a symptom such as a burnt connector to the design, assembly or usage cause behind it.

A snapshot of sensor and actuator values recorded by the engine control unit at the moment a fault code was set, used to recreate the conditions under which the fault occurred.

A fault code stored during the first detection cycle that has not yet met the criteria to become confirmed, giving early warning of an intermittent problem.

A self-test the control unit runs on an emissions-related system, whose completed or incomplete status shows whether the vehicle is ready for an emissions test.

Real-time readings of sensor inputs and calculated outputs streamed from a control unit, compared against expected values to isolate a faulty signal or component.

A recorded waveform of a voltage or current signal over time, used to judge the shape, amplitude and timing of pulses that a multimeter would average or miss.

A measurement of the potential difference across a connection or cable while current flows, revealing resistance that a simple continuity check would not show under load.

Current drawn from the battery when the vehicle is switched off and all systems have gone to sleep, measured to trace a component that is flattening the battery overnight.

A twisted-pair serial network that lets control units exchange data, diagnosed by checking termination resistance, bus voltage levels and signal integrity with a scope.

A single-wire, low-speed serial network used for simple body components such as mirrors and seats, with one master controller and several slave nodes.

The safe disconnection of a traction battery system, including proving the absence of voltage and securing the vehicle, before work on hybrid or electric powertrains begins.

A measurement of leakage between a high-voltage conductor and chassis earth using an insulated tester, confirming the system is safe and sound before and after repair.

A tightening method where a fastener is torqued to a set figure and then rotated through a further angle, stretching it into its elastic limit so it must be replaced each time.

A measurement of distortion across the head face using a straight edge and feeler gauge in several directions, deciding whether resurfacing or replacement is required.

A calibrated plastic thread placed across a bearing journal and crushed by the tightened cap, whose flattened width indicates the oil clearance.

The slight interference designed into a shell bearing so it is held firmly in its housing, checked by measuring the amount the shell stands proud of the cap face.

The amount a rotating part such as a shaft, disc or hub deviates from true rotation, measured with a dial gauge to diagnose vibration or uneven wear.

The process of tracing vibration under braking to disc thickness variation, runout, hub corrosion or uneven pad deposit, confirmed by measurement rather than guesswork.

Adjustment of camber, caster and toe at all four wheels against the manufacturer's specification, with thrust angle checked so the vehicle tracks straight.

The direction the rear axle points relative to the vehicle centreline, which must be corrected before front alignment so the steering wheel sits straight.

A road or stall check that reveals whether the clutch fails to transmit full engine torque, indicated by rising engine speed without matching road speed.

A measurement of hydraulic pressure in an automatic transmission at specified engine speeds and ranges, compared with specification to locate internal leakage or pump wear.

A documented check of a vehicle before handover covering fluids, fasteners, function of all systems, software status and cosmetic condition, signed off by the technician.

A defined route and set of driving conditions used to confirm a repair under the circumstances that originally produced the fault, with results recorded.

A checkpoint in a workshop process where defined inspection criteria must be met before the job can move to the next stage or be released to the customer.

The record of work authorised, parts used, labour time and technician findings for a vehicle, forming both the instruction to the workshop and the history of the repair.

Planning which jobs go to which bay and technician and when, balancing skills, equipment availability and promised completion times to keep the workshop productive.

The stage in a process with the least capacity, which limits the output of the whole workshop and should be the first target for improvement.

Explicit agreement from the customer, recorded in writing or on the job card, to carry out additional work and cost beyond the original instruction.

The person who translates the customer's complaint into a technical instruction for the workshop and explains the findings, costs and timescales back to the customer.