Pinpoint Test B: Poor Quality/Distorted/No Sound From One Or More Speakers (Not All Speakers)

Information and Entertainment System

Pinpoint Test B: Poor Quality/Distorted/No Sound From One Or More Speakers (Not All Speakers)

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

Normal Operation

When the key is placed in START, voltage is sent to the audio unit through the START sense circuit. When the audio unit receives this signal, it mutes the speaker signals. After the key is removed from START, the audio unit directs audio signals to the speakers through separate positive and negative circuits. The audio unit provides internal circuit protection for shorts to ground, shorts to battery, or shorts between any output circuits.

- DTC B2965 (Audio System Speaker Circuit Fault) - sets when the audio unit detects a circuit failure in any of the speaker circuits.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Speaker
- Audio unit


PINPOINT TEST B: POOR QUALITY/DISTORTED/NO SOUND FROM ONE OR MORE SPEAKERS (NOT ALL SPEAKERS)

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

NOTE: Use the speaker walk-around test to determine which speaker(s) has a concern.

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B1 CHECK THE SPEAKER CIRCUITS FOR AN OPEN OR SHORT TO GROUND


- Ignition OFF.
- Disconnect: Audio Unit C290a.
- Disconnect: Suspect Speaker(s).
- Measure the resistance between the suspect speaker connector, harness side and the audio unit connector, harness side; and between the suspect speaker connector, harness side and ground as follows:









- Is the resistance less than 5 ohms between the suspect speaker and the audio unit, and greater than 10,000 ohms between the suspect speaker and ground?

Yes
GO to B2.

No
REPAIR the circuit in question. TEST the system for normal operation.

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B2 CHECK THE SPEAKER CIRCUITS FOR A SHORT TO VOLTAGE


- Ignition ON.
- Measure the voltage between the suspect speaker connector, harness side and ground as follows:









- Is any voltage present?

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

No
GO to B3.

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B3 CHECK THE SPEAKER


- Ignition OFF.
- Connect: Audio Unit C290a.
- Substitute a known good speaker for the suspect speaker.
- Is the sound quality OK?

Yes
INSTALL a new speaker. REFER to Speaker - Door Speaker - Door or Speaker - Parcel Shelf Speaker - Parcel Shelf. TEST the system for normal operation.

No
INSTALL a new audio unit. REFER to Audio Unit Service and Repair. TEST the system for normal operation.

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