Pinpoint Test F: Poor Quality/Distorted/No Sound From All Speakers - Except Sony(R) Sound

Information and Entertainment System

Pinpoint Test F: Poor Quality/Distorted/No Sound From All Speakers - Except Sony(R) Sound

Refer to Wiring Diagram Set 130, Audio System/Navigation for schematic and connector information. Diagrams By Number

Normal Operation

When the ignition is in the START position, voltage is supplied to the Audio Control Module (ACM) through the START sense circuit. When the ACM (Audio Control Module) receives this voltage, it mutes the speaker output. However, if there is a short to voltage on this circuit, the ACM (Audio Control Module) continuously mutes the audio output, resulting in no sound from all speakers.

This pinpoint test is intended to diagnose the following:

- Fuse

- Wiring, terminals or connectors

- ACM (Audio Control Module)

PINPOINT TEST F : POOR QUALITY/DISTORTED/NO SOUND FROM ALL SPEAKERS - EXCEPT SONY(R) SOUND

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

NOTE: Failure to disconnect the battery when instructed will result in false resistance readings.

F1 CHECK THE START SENSE CIRCUIT FOR A SHORT TO VOLTAGE

- Ignition OFF.

- Disconnect: ACM (Audio Control Module) C240A.

- Ignition ON.

- Measure the voltage between the ACM (Audio Control Module) C240A-15, circuit CBP28 (GY/VT), harness side and ground.





Is any voltage present?

Yes
REPAIR the circuit. TEST the system for normal operation.

No
GO to F2.

F2 CHECK FOR CORRECT ACM (Audio Control Module) OPERATION

- Ignition OFF.

- Disconnect all the ACM (Audio Control Module) connectors.

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect all the ACM (Audio Control Module) connectors and make sure they seat correctly.

- Operate the system and determine if the concern is still present.

Is the concern still present?

Yes
INSTALL a new ACM (Audio Control Module). REFER to Audio Control Module (ACM) . TEST the system for normal operation.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.