Pinpoint Test B: Poor Quality Or No Sound From One Or More Speakers (Not All Speakers) - Vehicles Without Sony(R) Sound
Information and Entertainment System
Pinpoint Tests
Pinpoint Test B: Poor Quality Or No Sound From One Or More Speakers (Not All Speakers) - Vehicles Without Sony(R) Sound
Refer to Wiring Diagram Set 130, Audio System/Navigation for schematic and connector information. Diagrams By Number
NOTE: In Normal Operation, the terms Audio Control Module (ACM) and in-dash computer are synonymous.
Normal Operation
The ACM directs audio signals to the speakers in the form of an AC voltage. The ACM provides internal circuit protection for shorts to ground or shorts to voltage.
A short to ground or short to voltage in the circuitry to one of the speakers can 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 (all except base AM/FM ACM), and this pinpoint test should be followed to isolate the damaged circuit.
The speaker walk test can be used to isolate a concern with a particular speaker. This can reduce the diagnostic steps necessary to isolate the concern. To carry out the speaker walk test, refer to Audio Control Module (ACM) Self-Diagnostic Mode Audio Control Module (ACM) Self-Diagnostic Mode.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Speaker
- ACM (vehicles without Ford Work Solutions(TM))
- In-dash computer (vehicles with Ford Work Solutions(TM))
PINPOINT TEST B: POOR QUALITY OR NO SOUND FROM ONE OR MORE SPEAKERS (NOT ALL SPEAKERS) - VEHICLES WITHOUT 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.
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B1 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, Speaker - Instrument Panel Speaker - Instrument Panel or Speaker - A-Pillar Speaker - A-Pillar. CLEAR any DTCs present. TEST the system for normal operation.
No
GO to B2.
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B2 CHECK THE CIRCUITS TO THE SUSPECT SPEAKER FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: ACM C290A (In-Dash Computer C2408A).
- 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 B3.
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B3 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 or (in-dash computer), 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 (in-dash computer) and greater than 10,000 ohms between the suspect speaker and ground?
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 FOR CORRECT ACM (IN-DASH COMPUTER) OPERATION
- Ignition OFF.
- Connect: All Disconnected Connectors.
- Disconnect all the ACM (in-dash computer) connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the ACM (in-dash computer) 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 (in-dash computer). REFER to Audio Control Module (ACM) Audio Control Module (ACM) or In-Dash Computer In-Dash Computer. 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 any DTCs present.
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