Audio — Ambient noise and outside (vehicle-induced) noise
J-17prose procedure2. Ambient noise
(1) Fading (AM)
As the distance between the source and the receiver increases, AM radio waves from other sources, reflecting off the ionosphere, interfere with the original source radio waves. Reception strength is lowered and sound quality is reduced. This effect is called fading.
(2) Fast fading (FM)
Fast fading is noise or sound distortion caused by mountains or buildings obstructing the FM radio waves.
(3) Multipath noise (FM)
Multipath noise occurs when the radio antenna picks up a direct wave and a reflected wave at the same time.
Since ambient noise is a temporary occurrence, it will be solved when vehicle location changes.
3. Outside noise (vehicle-induced noise)
Outside noise (vehicle-induced noise) — Name of noise / Condition
Noise when engine is started
Noise when engine is started
Name of noiseFuel pump noise
ConditionNoise occurs immediately after ignition switch is turned to ON
Noise when engine is started
Noise when engine is started
Name of noiseIgnition noise
ConditionConsecutive noise. Tone changes when acceleration pedal is depressed
Noise when engine is started
Noise when engine is started
Name of noiseAlternator noise
ConditionWhizzing noise occurs when acceleration pedal is depressed
Noise when electrical parts are operated
Noise when electrical parts are operated
Name of noiseWiper motor noise
ConditionHowling noise occurs synchronized with wiper operation
Noise when electrical parts are operated
Noise when electrical parts are operated
Name of noiseWasher motor noise
ConditionNoise occurs when window washer is operated
Noise when electrical parts are operated
Noise when electrical parts are operated
Name of noisePower window noise
ConditionNoise occurs when power window is operated
Noise when electrical parts are operated
Noise when electrical parts are operated
Name of noiseFan motor noise
ConditionNoise occurs when fan is operated
Noise when electrical parts are operated
Noise when electrical parts are operated
Name of noiseStoplight noise
ConditionNoise occurs at beginning or end of brake operation
Noise when electrical parts are operated
Noise when electrical parts are operated
Name of noiseTurn signal noise
ConditionClicking noise occurs synchronized with signal flash
Noise when electrical parts are operated
Noise when electrical parts are operated
Name of noiseHorn switch noise
ConditionWhizzing noise occurs when acceleration pedal is depressed
Noise when electrical parts are operated
Noise when electrical parts are operated
Name of noiseAir conditioner noise
ConditionHowling noise occurs when air conditioner is operated
Although it is difficult to eliminate these noises, they can be reduced by installing a noise suppressor or noise-preventive capacitor near the electrical system which emits the noise current. For example, to reduce wiper motor noise, install noise-preventive capacitors near the wiper motor. If there is no change after installing the capacitors, make sure the circuit is properly ground.