Confirm the version and baseline
Record the exact EV version, driven-wheel configuration, wheel and tyre package, mileage and repair history. Ask when the sound began and whether it changed after a tyre replacement, impact, underbody repair or service. Keep the seller's description separate from the inspector's observation. The Song Plus identity guide prevents a hybrid or another market's drivetrain information entering the diagnosis. Do not compare a recording from an unrelated car as a definitive normal reference. Audio compression, microphone position and road surface can all change how a sound appears remotely.
Map the sound during ordinary driving
Use a safe legal route with a qualified driver and a separate observer or mounted recording device. Note road speed, acceleration, steady load, coasting, braking, cornering, temperature and surface. Keep the settings and route consistent when repeating a symptom. Do not ask the driver to handle a phone or make abrupt manoeuvres to provoke noise. A sound tied to wheel speed suggests a different investigation from one that changes mainly with applied torque, but neither observation is a diagnosis by itself. Record what happens rather than attaching a component name too early.
Eliminate accessible non-drive-unit causes
Inspect tyre condition and matching, wheel damage, loose shields, cargo and trim through a normal workshop process. Review wheel bearings, suspension and brake condition where the symptoms indicate them. The tyre, brake and regeneration checks help separate braking-related changes from propulsion noise. A stone, bent shield or uneven tyre can imitate a more expensive problem. Do not reach near moving wheels, crawl under an unsupported vehicle or run the drivetrain on improvised stands. Physical inspection must use appropriate equipment and safe procedures, not a roadside attempt to localise sound by touch.
Preserve diagnostics and repair evidence
Obtain a VIN-linked scan before clearing faults and ask which relevant modules were covered. Review drive-unit service or replacement invoices and any evidence of leakage, impact or disturbed mountings. Use only the applicable service information when checking fluids or maintenance requirements; no universal lubricant or interval should be assumed. The underbody and repair-history guide is relevant when noise follows an impact. Absence of a warning code does not prove that every mechanical component is sound, and a stored code needs interpretation rather than automatic replacement of the named assembly.
Define the workshop question narrowly
Give the technician the symptom map and ask for the next test that can distinguish the leading causes. The required work may involve specialist listening equipment, measurements or manufacturer procedures. Do not authorise a complete drive-unit replacement solely because a seller or remote listener describes a whine. Equally, do not accept a claim that all EVs sound like that when the symptom is new, severe or accompanied by vibration, warnings or loss of performance. The workshop should explain what evidence supports its conclusion and what uncertainty remains, including any need for further access or testing.
Make repair support part of valuation
If the cause is diagnosed, obtain an itemised repair scope, correct component identification and a destination support plan. Ask how the original symptom will be reproduced and checked after repair. A quiet short demonstration on a different road may not cover the original condition. Use the parts and maintenance plan to price availability and downtime as well as labour. For a used purchase, unresolved significant noise can justify holding or rejecting the candidate. New vehicles also deserve investigation of abnormal delivery symptoms rather than an assurance that a break-in period will inevitably cure them.
Use the evidence in a real buying decision
A hum that changes substantially after crossing from one road surface to another deserves a tyre and road-noise comparison before a drive-unit quotation. A load-dependent sound that persists across surfaces may point the investigation elsewhere. Neither pattern proves the cause alone. Give the technician both observations and retain the original route record so the repair can be checked under the conditions that produced the complaint.
Buyer checklist
- Exact EV, wheels and repair history
- Repeatable speed, load and temperature map
- Tyres, bearings, brakes and shields assessed
- Original scan and supported repair conclusion
Questions and answers
Is every electric-motor whine a defect?
No. Some operating sound may be normal, but unusual or changing noise needs assessment in context.
Can a phone recording identify a failed reduction gear?
Not reliably on its own. Use the recording to document conditions and support an appropriate physical diagnosis.
Manufacturer reference
Use the applicable market and year documentation for equipment and operating limits. These model references do not establish the condition, fitted equipment or destination approval of an individual vehicle.
Continue with the Song Plus inspection checklist, or send your vehicle requirements.