Pinpoint Test D: No Sound From All Speakers
Information and Entertainment System
Pinpoint Tests
Pinpoint Test D: No Sound From All Speakers
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 - Vehicles Without Sony(R) Sound
When the ignition is in the START position, voltage is supplied to the Audio Control Module (ACM) through the start sense circuit. When the ACM receives this voltage, it mutes the speaker output to prevent popping in the speakers as a result of voltage spikes during engine cranking, However, if there is a short to voltage on this circuit, the ACM continuously mutes the audio output, resulting in no sound from all speakers.
Sony(R) Sound
When the ignition is in the START position, voltage is supplied to the ACM through the start sense circuit. When the ACM receives this voltage, the ACM uses a mute circuit to mute the audio Digital Signal Processing (DSP) module. This prevents popping in the speakers as a result of voltage spikes during engine cranking. The audio DSP module is muted if less then 3.5 volts is detected on the mute circuit. The audio DSP module is enabled through software. An open or short to ground in the mute circuit causes the audio system to produce no sound.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Audio DSP module
- ACM (vehicles without Ford Work Solutions(TM))
- In-dash computer (vehicles with Ford Work Solutions(TM))
PINPOINT TEST D: POOR QUALITY/DISTORTED/NO SOUND FROM ALL SPEAKERS
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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D1 CHECK THE START SENSE CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: ACM C290A (In-Dash Computer C2408A).
- Ignition ON.
- Measure the voltage between the ACM (in-dash computer) C290A-15 (C2408A-15), circuit CDC54 (WH/GN), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit. TEST the system for normal operation.
No
For vehicles with Sony(R) Sound, GO to D2.
For vehicles without Sony(R) Sound, GO to D7.
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D2 CHECK THE AUDIO DSP MODULE VOLTAGE SUPPLY
- Ignition OFF.
- Disconnect: Audio DSP Module C3154C.
- Measure the voltage between the audio DSP module, harness side and ground as follows:
- Are the voltages greater than 10 volts?
Yes
GO to D3.
No
VERIFY BCM fuse 19 (20A) is OK. If OK, REPAIR the circuit in question. TEST the system for normal operation. If not OK, Refer to the Wiring Diagrams to identify the possible causes of the circuit short. Diagrams By Number
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D3 CHECK THE AUDIO DSP MODULE GROUND CIRCUITS FOR CONTINUITY
- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Measure the resistance between the audio amplifier, harness side and ground as follows:
- Are the resistances less than 5 ohms?
Yes
GO to D4.
No
REPAIR the circuit in question. TEST the system for normal operation.
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D4 CHECK THE AUDIO DSP MODULE MUTE CIRCUIT FOR CORRECT VOLTAGE
- Connect: Audio DSP Module C3154C.
- Connect: Negative Battery Cable.
- Disconnect: Audio DSP Module C3154A.
- Operate the audio system in radio tuner (AM/FM) mode.
- Measure the voltage between the audio DSP module C3154A-3, circuit SME23 (VT/RD), harness side and ground.
- Is the voltage at least 3.5 volts?
Yes
GO to D8.
No
GO to D5.
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D5 CHECK THE AUDIO DSP MODULE ENABLE CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: ACM C290A.
- Measure the voltage between the audio DSP module C3154A-3, circuit SME23 (VT/RD), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit. TEST the system for normal operation.
No
GO to D6.
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D6 CHECK THE AUDIO DSP MODULE ENABLE CIRCUIT FOR AN OPEN OR SHORT TO GROUND
- For vehicles with navigation, measure the resistance between the audio DSP module C3154A-3, circuit SME23 (VT/RD), harness side and the ACM C290A-7, circuit SME23 (VT/RD), harness side; and between the audio DSP module C3154A-3, circuit SME23 (VT/RD), harness side and ground.
- For vehicles without navigation, measure the resistance between the audio DSP module C3154A-3, circuit SME23 (VT/RD), harness side and the ACM C290D-4, circuit SME23 (VT/RD), harness side; and between the audio DSP module C3154A-3, circuit SME23 (VT/RD), harness side and ground.
- Is the resistance less than 5 ohms between the audio DSP module and the ACM, and greater than 10,000 ohms between the audio DSP module and ground?
Yes
GO to D7.
No
REPAIR the circuit. TEST the system for normal operation.
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D7 CHECK FOR CORRECT ACM (IN-DASH COMPUTER) OPERATION
- Ignition OFF.
- 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.
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D8 CHECK FOR CORRECT AUDIO DSP MODULE OPERATION
- Ignition OFF.
- Connect: All Disconnected Connectors.
- Disconnect all the audio DSP module connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the audio DSP module 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 audio DSP module. REFER to Audio Digital Signal Processing (DSP) Module - Front Captain's Chair Audio Digital Signal Processing (DSP) Module - Front Captain's Chair or Audio Digital Signal Processing (DSP) Module - Split Bench Audio Digital Signal Processing (DSP) Module - Split Bench. 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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