Pinpoint Test AG: Poor Quality/Distorted/No Sound From All Speakers - Except THX(R) Audio System

Information and Entertainment System

Pinpoint Tests

Pinpoint Test AG: Poor Quality/Distorted/No Sound From All Speakers - Except THX(R) Audio System

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

Normal Operation

The Audio Control Module (ACM) receives voltage with the ignition in the START position through circuit CBP13 (GY/BN). When it receives this voltage, it mutes the audio output in order to reduce the possibility of popping sounds due to voltage spikes during engine cranking. However, if this circuit is short to voltage, the ACM will continuously mute the audio output.

In addition, a circuit failure on any of the speaker output circuits may cause the ACM to go into overload protection mode, muting the output to the speakers. If there is such a circuit failure, DTC B2965 will be set.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- ACM



PINPOINT TEST AG: NO SOUND FROM ALL SPEAKERS - EXCEPT THX(R) AUDIO SYSTEM

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

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AG1 CHECK THE ACM DTCs


- Carry out the ACM self-test.
- Is DTC B2965 retrieved?

Yes
Go To Pinpoint Test B.

No
GO to AG2.

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AG2 CHECK CIRCUIT CBP13 (GY/BN) FOR A SHORT TO VOLTAGE


- Ignition OFF.
- Disconnect: ACM C240a or C290a.
- Disconnect: Smart Junction Box (SJB) C2280b.
- Ignition ON.
- Measure the voltage between the ACM C240a-15 or C290a-15, circuit CBP13 (GY/BN), harness side and ground.




- Is any voltage present?

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

No
GO to AG3.

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AG3 CHECK THE ACM FOR CORRECT OPERATION


- Connect: SJB C2280b.
- Ignition OFF.
- Disconnect all the ACM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the ACM 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. REFER to Audio Control Module (ACM) - Fusion, Milan Audio Control Module (ACM) - Fusion, Milan or Audio Control Module (ACM) - MKZ . 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.

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