松电门减速突然变弱，先看回收限制；机械制动异常则必须另查

Regenerative deceleration can vary with vehicle state. The cited Model 3 manual gives cold or high battery charge as examples of limits, but features and messages vary. Record temperature, charge, warnings and recent charging or parking conditions. Follow the actual owner's manual and remain ready to use the brake pedal with adequate distance. A change in regeneration must not explain away abnormal pedal travel, pulling, reduced braking or brake warnings. Those require separate assessment. Friction brakes still need their prescribed care. Do not provoke the condition in traffic or on a downhill road; let qualified staff perform any necessary controlled verification.