Pinpoint Test B: Poor Quality/Distorted/No Sound From One Or More Speakers (Not All Speakers) - Except THX(R) Audio System
Information and Entertainment System
Pinpoint Tests
Pinpoint Test B: Poor Quality/Distorted/No Sound From One Or More Speakers (Not 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) directs the audio signals to the speakers through separate positive and negative circuits for each of the 4 audio channels: LH front, RH front, LH rear, and RH rear. The ACM provides internal circuit protection for shorts to ground or shorts to voltage. For vehicles with door tweeter speakers, the speakers are wired in series with the door speakers.
For the navigation system, if the voice guidance setting is set to zero rather than to off, it may appear that the front speakers intermittently produce no sound. Make sure the voice guidance setting is not set to zero before addressing a concern with the front speakers.
- DTC B2965 (Audio System Speaker Circuit Fault) - sets when a short to ground is detected on any of the speaker circuits. For all audio systems except single CD, DTC B2965 also sets when an open circuit or short to voltage is detected.
For some audio systems, a short to ground or short to voltage in the circuitry to one of the speakers will cause all speakers to lose sound due to the built-in overload protection feature of the ACM. In this case, DTC B2965 will set in the ACM, and this pinpoint test should be followed to isolate the damaged circuit.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Speaker
- ACM
PINPOINT TEST B: POOR QUALITY/DISTORTED/NO SOUND FROM ONE OR MORE SPEAKERS (NOT 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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B1 ISOLATE THE SUSPECT SPEAKER
- Carry out the speaker walk-around test.
- Is the concern with a tweeter speaker?
Yes
GO to B5.
No
GO to B2.
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B2 CHECK THE SPEAKER CIRCUITS FOR VOLTAGE
- Ignition OFF.
- Disconnect: Suspect Speaker.
- Operate the audio system in radio tuner (AM/FM) mode.
- Measure the AC voltage between the suspect speaker pin 1 and pin 2, harness side as follows:
- Is a fluctuating AC voltage present?
Yes
INSTALL a new speaker for the suspect speaker. REFER to Speaker - Door Speaker - Door or Speaker - Parcel Shelf Speaker - Parcel Shelf. CLEAR the DTCs. REPEAT the self-test.
No
GO to B3.
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B3 CHECK THE SPEAKER CIRCUITS FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: ACM C290a.
- Ignition ON.
- Measure the voltage between the suspect speaker, harness side and ground as follows:
- Is any voltage present?
Yes
REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.
No
GO to B4.
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B4 CHECK THE SPEAKER CIRCUITS FOR AN OPEN OR SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between the ACM, harness side and the suspect speaker, harness side; and between the ACM, harness side and ground as follows:
- Are the resistances less than 5 ohms between the ACM and the speaker, and greater than 10,000 ohms between the ACM and ground?
Yes
GO to B9.
No
REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.
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B5 CHECK FOR VOLTAGE TO THE SUSPECT TWEETER SPEAKER
- Ignition OFF.
- Disconnect: Suspect Tweeter Speaker.
- Operate the audio system in radio tuner (AM/FM) mode.
- Measure the AC voltage between the suspect tweeter speaker pin 1 and pin 2, harness side as follows:
- Is a fluctuating AC voltage present?
Yes
INSTALL a new speaker for the suspect tweeter speaker. REFER to Speaker - Door Speaker - Door. CLEAR the DTCs. REPEAT the self-test.
No
GO to B6.
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B6 CHECK THE TWEETER SPEAKER CIRCUITS FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: LF Speaker C513 or RF Speaker C613.
- Ignition ON.
- Measure the voltage between the suspect tweeter speaker, harness side and ground as follows:
- Is any voltage present?
Yes
REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.
No
GO to B7.
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B7 CHECK THE TWEETER SPEAKER CIRCUITS FOR AN OPEN OR SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between the suspect tweeter speaker, harness side and the respective door speaker, harness side; and between the suspect tweeter speaker, harness side and ground as follows:
- Is the resistance less than 5 ohms between the suspect tweeter speaker and the door speaker, and greater than 10,000 ohms between the suspect tweeter speaker and ground?
Yes
GO to B8.
No
REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.
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B8 ISOLATE THE DOOR SPEAKER
- Connect: Suspect Tweeter Speaker.
- Install a known good door speaker for the door with the suspect tweeter speaker.
- Operate the audio system in radio tuner (AM/FM) mode.
- Does the tweeter speaker operate correctly?
Yes
INSTALL a new door speaker. REFER to Speaker - Door Speaker - Door. CLEAR the DTCs. REPEAT the self-test.
No
INSTALL a new tweeter speaker. REFER to Speaker - Door Speaker - Door. CLEAR the DTCs. REPEAT the self-test.
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B9 CHECK FOR CORRECT ACM OPERATION
- 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. CLEAR the DTCs. REPEAT the self-test.
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