Pinpoint Test B: Poor Quality/Distorted/No Sound From One Or More Speakers (Not All Speakers) - Premium Sound Or Audiophile Wit
Information and Entertainment System
Pinpoint Tests
Pinpoint Test B: Poor Quality/Distorted/No Sound From One Or More Speakers (Not All Speakers) - Premium Sound Or Audiophile Without Navigation
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 audio signals to the speakers in the form of a fluctuating AC voltage. The tweeter speakers (Audiophile only) are wired in series with the front door speakers.
A short to ground or short to voltage in the circuitry to one of the speakers may cause multiple speakers to lose sound due to the built-in overload protection feature of the ACM. In this case, a speaker fault DTC sets, and this pinpoint test should be followed to isolate the damaged circuit.
- DTC B2965 (Audio System Speaker Circuit Fault) - set by the ACM when a failure is detected in any of the speaker circuits.
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) - PREMIUM SOUND OR AUDIOPHILE WITHOUT NAVIGATION
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 DETERMINE THE INOPERATIVE SPEAKER
- Ignition ON.
- Carry out the speaker walk test. Refer to Audio Control Module (ACM) Self-Diagnostic Mode Audio Control Module (ACM) Self-Diagnostic Mode.
- Is the concern only with a tweeter speaker?
Yes
GO to B5.
No
GO to B2.
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B2 CHECK THE AUDIO SIGNALS TO THE SUSPECT SPEAKER
- 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. TEST the system for normal operation.
No
GO to B3.
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B3 CHECK THE CIRCUITS TO THE SUSPECT SPEAKER FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: ACM C240a.
- Ignition ON.
- Measure the voltage between the suspect speaker pins, harness side and ground as follows:
- Is any voltage present?
Yes
REPAIR the circuit in question. CLEAR any DTCs present. TEST the system for normal operation.
No
GO to B4.
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B4 CHECK THE CIRCUITS TO THE SUSPECT SPEAKER FOR AN OPEN OR SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between the suspect speaker, harness side and the ACM, harness side; and between the suspect speaker, harness side and ground as follows:
- Is the resistance less than 5 ohms between the suspect speaker and the ACM, and greater than 10,000 ohms between the suspect speaker and ground?
Yes
GO to B8.
No
REPAIR the circuit in question. CLEAR any DTCs present. TEST the system for normal operation.
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B5 CHECK THE AUDIO SIGNALS 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. TEST the system for normal operation.
No
GO to B6.
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B6 CHECK THE CIRCUITS TO THE SUSPECT TWEETER SPEAKER FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: LF Door Speaker C570b or RF Door Speaker C612b.
- 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. TEST the system for normal operation.
No
GO to B7.
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B7 CHECK THE CIRCUITS TO THE SUSPECT TWEETER SPEAKER 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:
Edge:
MKX:
- 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
INSTALL a new door speaker. REFER to Speaker - Door Speaker - Door. TEST the system for normal operation.
No
REPAIR the circuit in question. TEST the system for normal operation.
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B8 CHECK FOR CORRECT ACM OPERATION
- Ignition OFF.
- Connect: All Disconnected Connectors.
- 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) 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.
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