NO.1 AF NOISE OR POP NOISE ON ALL SOURCES (RADIO, CD, CASSETTE TAPE)

Note

• AF noise is "Petit Petit" noise that generally occurs with switch ON/OFF operations of electrical equipment other than the audio unit, or "Gee" continual noise that occurs when electrical equipment is operated.This is caused by noise entrance to the power supply wiring, signal wiring, speaker cable or head of cassette deck etc. Therefore noise can be heard regardless of radio wave condition or audio volume position. The noise will start after one click from the minimum position of volume button but normally does not change even when volume is turned to higher position.

• POP noise is "Putsun", "Poco" or "Putsun" noise that occurs with switch ON/OFF operation of the audio unit, or with switching Radio to CD. Even normal audio unit sometimes emit small noise depending on conditions.

Diagnostic procedure

STEP	INSPECTION		ACTION
1	• Inspect the vehicle battery voltage. • Is the vehicle battery voltage normal? Specification: Ignition switch ON: 11.5 V or more Idle: 12.5 V or more	Yes	Go to the next step.
		No	Charge the battery, then go to next step.
2	• Turn the audio system to ON. • Is there any noise?	Yes	Go to the next step.
		No	The system is normal. Explain to the customer that the vehicle battery voltage was low.
3	• Is any of the following after-market equipment installed? (Inspect especially hear the GPS antenna.) - Reader - Remote engine starter - Anti-theft device - Other	Yes	Go to the next step.
		No	Go to the Step 5.
4	• Remove the after-market equipment. • Turn the audio system to ON. • Is there any noise?	Yes	Go to the next step.
		No	The system is normal. The after-market electrical devices might make a noise.
5	• Is there the noise from all speakers?	Yes	Go to the Step 7.
		No	Go to the next step.
6	• Inspect the suspect speaker. • Is the speaker normal?	Yes	Go to the next step.
		No	If there is any foreign material on the speaker • Remove the foreign material from the speaker. If the speaker is malfunctioning • Replace the speaker. If the speaker is not installed properly • Install the speaker properly.
7	• Attempt to duplicate the symptom on the other vehicle. • Is the noise better than the customer's vehicle?	Yes	Go to the next step.
		No	The system is normal. Explain the noise generation mechanism to the customer. Note • The noise may be heard depends on the operating speed of audio power and/or mode switch.
8	• Is there any noise from the woofer speaker?	Yes	Go to the next step.
		No	Go to the Step 11.
9	• Remove the woofer unit. • Inspect the connection of the woofer unit connector (6-pin) terminal A (B+), B (GND), G (WOOF IN+) and H (WOOF IN-). • Is the connector connected securely?	Yes	Replace the woofer unit.
		No	Repair or replace the terminal or connector. Go to the next step.
10	• Is there any noise?	Yes	Replace the woofer unit.
		No	The system is normal.
11	• Turn the ignition switch to the LOCK position. • Remove the audio unit. • Inspect the connection of the audio unit connector (24-pin) (for sound signal line). • Is the connector connected securely?	Yes	Go to the Step 13.
		No	Repair or replace the terminal or connector. Go to the next step.
12	• Is there any noise?	Yes	Go to the next step.
		No	The system is normal.
13	• Turn the ignition switch to the LOCK position. • Disconnect the BOSE amplifier unit connector. • Inspect the continuity between the BOSE amplifier unit wiring harness connector (26-pin) terminal V and ground. • Is there continuity?	Yes	Go to the Step 15.
		No	Repair or replace the terminal or connector. Go to the next step.
14	• Is there any noise?	Yes	Go to the next step.
		No	The system is normal.
15	• Inspect the ground condition of the antenna. • Is the ground condition normal?	Yes	Replace the BOSE amplifier unit.
		No	Repair or replace the ground. Go to the next step.
16	• Is there any noise?	Yes	Replace the BOSE amplifier unit.
		No	The system is normal.