Front Tweeter Circuit Check

Front Tweeter Circuit Check

Description

The audio unit sends audio signals to the audio amplifier The audio amplifier amplifies the audio signals before sending them to the tweeters using the audio signal circuits.

Diagnosis Procedure

Regarding Wiring Diagram information, refer to [Premium Audio System: Wiring Diagram [Crew Cab] Premium Audio System [Crew Cab] ].

1. CONNECTOR CHECK

Check the audio unit, audio amplifier and speaker connectors for the following:
- Proper connection
- Damage
- Disconnected or loose terminals

Is the inspection result normal?
YES
GO TO 2.
NO
Repair the terminal and connector.

2. HARNESS CHECK

1 Disconnect audio amplifier connector B159 and suspect tweeter connector.





2 Check continuity between audio amplifier harness connector B159 (A) and suspect tweeter harness connector (B).






3 Check continuity between audio amplifier harness connector B159 (A) and ground.






Are continuity test results as specified?
YES
GO TO 3
NO
- Check connector housings for disconnected or loose terminals.
- Repair or replace harness or connector.

3. FRONT TWEETER SIGNAL CHECK

1 Connect audio amplifier connector B159 and suspect tweeter connector.





2 Turn ignition switch to ACC.
3 Push audio unit "POWER" switch.
4 Check the signal between audio amplifier harness connector B159 terminals with SDT or oscilloscope.






Is audio signal voltage as specified?
YES
Replace suspect tweeter. Refer to [Front Tweeter: Removal and Installation] Front Tweeter.
NO
GO TO 4

4. PRE-AUDIO AMPLIFIER HARNESS CHECK

1 Disconnect audio unit connector M65 and audio amplifier connector B159.





2 Check continuity between audio unit harness connector M65 (A) and audio amplifier harness connector B159 (B).






3 Check continuity between audio unit harness connector M65 (A) and ground.






Are continuity test results as specified?
YES
GO TO 5
NO
- Check connector housings for disconnected or loose terminals.
- Repair or replace harness or connector.

5. PRE-AUDIO AMPLIFIER SIGNAL CHECK

1 Connect audio unit connector and audio amplifier connector.





2 Turn ignition switch ACC.
3 Push audio unit "POWER" switch.
4 Check the signal between audio unit harness connector M65 terminals with SDT or oscilloscope.






Are the audio signal voltage readings as specified?
YES
Replace audio amplifier Refer to [Audio AMP: Removal and Installation] Service and Repair.
NO
Replace audio unit. Refer to [Audio Unit: Removal and Installation] Audio Unit.