Inspection Procedure 17

INSPECTION PROCEDURE 17: Noise: Noise is present while moving (FM).

DIAGNOSIS

STEP 1. Check the radio after adjusting it.

Q. Readjust the radio. Is the noise eliminated?

YES Check that there is no noise.

NO Go to Step 2.

STEP 2. Check with several broad casting.

NOTE:
Multipath noise and fading noise: Because of the frequency of FM waves in extremely high, it is highly susceptible to effects from geological formations and buildings. These effects disrupt the broadcast signal and obstruct reception in several ways.

- Multipath noise
This describes 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).
- Fading noise
This is a buzzing noise that occurs when the broadcast signal is disrupted by obstructing objects and the signal strength fluctuates intricately within a narrow range.

Q. Is the problem station or location specific?

YES The effect of an electrical field condition (multipath noise, fading noise) could be the cause. Check that there is not noise.

NO Go to Step 3.

STEP 3. Check that noise appears when the radio switch is turned on while the vehicle is stopped.

NOTE:
Body static electricity from the shock absorber rubber bushings used to prevent vibration, tires, etc. occurs because of separation from the ground, causing a buzzing noise. There are no measures to discharge the static electricity of the vehicle body. Check that there is no noise.

Q. Does noise appear when the radio switch is turned on while the vehicle is stopped and the radio is tapped while tuned away from a station?

YES Go to Step 4.

NO It may be static electricity noise.

STEP 4. Verify that the radio is correctly grounded.

Q. Is the radio correctly grounded?

YES Go to Step 5.

NO Check that there is no noise.

STEP 5. Check by replacing radio and CD player or radio and CD player with CD changer.

Q. Do the other radio and CD player or radio and CD player with CD changer work normally?

YES Repair or replace the original radio and CD player or radio and CD player with CD changer.

NO Either repair or replace the antenna assembly.