Inspection Procedure 6: Poor Reception.


DIAGNOSIS PROCEDURE


STEP 1. Check the state of the antenna.


Q. Is the mast antenna assembled?





STEP 2. Check to see if inspections are taking place is an area exposed to special electric fields.


Q. Are inspections taking place under special electric field conditions (underground garage, inside a building, etc.)?





STEP 3. Move the vehicle and check the radio.



Q. Is reception of the strongest radio frequency possible within the area?





STEP 4. Tune the radio, and then check it.


Q. Did the sensitivity improve after tuning?





STEP 5. Check with several broadcasting stations.


note Two types of noise are addressed in this procedure, multipath and fading noise. The frequency of FM waves is extremely high. This makes them susceptible to effects from geological formations and buildings. These effects disrupt the broadcast signal and obstruct reception in many ways.

  • Multipath noise is the echo that occurs when the broadcast signal is reflected by a large obstruction and enters the receiver with a slight time delay relative to the direct signal (repetitious buzzing).
  • A fading or buzzing noise may occur when the broadcast beam is disrupted by obstructing objects and the signal strength fluctuates within a narrow range.

Q. Is the abnormality in reception generated only within a certain range?





STEP 6. Check the connection of the antenna plug and audio visual navigation unit.


Q. Is the antenna plug thoroughly connected to the audio visual navigation unit?





STEP 7. Check by replacing audio visual navigation unit.


Q. Do the other audio visual navigation unit work normally?