Inspection Procedure 4: Noise Appears at Certain Places when Travelling.

DIAGNOSIS PROCEDURE

STEP 1. Check the noise occur when entering or near a particular structure (building, tunnel, mountain, etc).

Q. Does the noise occur when entering or near a particular structure (building, tunnel, mountain, etc.)?

Go to Step 3.

Go to Step 2.

STEP 2. After taking the following measures to prevent the noise, check that no noise appears.

(1)Change to a different station with a stronger wave to boost resistance to interference.

(2)Suppress high tones to reduce noise.

Q. Do the following measures eliminate the noise?

This diagnosis is complete.

Go to Step 4.

STEP 3. Ask the owner about the state of the noise.

Find out the following information from the owner.

Place where the noise occurs.
Locality conditions (valley, mountain, etc).
Name and frequency of stations affected by noise

Q. Which is the noise, vehicle noise or external noise?

Vehicle noise : It may not be possible to prevent noise if the signal is weak. This diagnosis is complete.

External noise

: In almost all cases, prevention on the receiver side is impossible. Weak signals especially are susceptible to interference. Go to Step 4.

STEP 4. Check that there is no noise.

Q. Does noise still exist?

If there is more noise than on radios in other vehicles, find out the noise condition and the name and frequency of the receiving stations from the owner, and consult with the radio manufacturer’s service centre.

Normal.