Pinpoint Test D: Poor Quality/Distorted/No Sound From All Speakers - Premium Sound
Information and Entertainment System
Pinpoint Test D: Poor Quality/Distorted/No Sound From All Speakers - Premium Sound
Refer to Wiring Diagram Set 130, Audio System/Navigation for schematic and connector information. Diagrams By Number
Normal Operation
The Remote Function Actuator (RFA) module sends a voltage signal to the Audio Control Module (ACM) when the ignition is in a START sequence. This prevents voltage spikes from creating a popping sound during engine cranking. However, if this circuit has a short to voltage or the RFA module sends the signal incorrectly, it results in the speaker output being continuously muted.
- DTC B125C:11 (Radio Mute Circuit: Short to Ground) - sets when the RFA module detects a short to ground on the mute circuit. This should not cause any observable audio system symptoms.
- DTC B125C:15 (Radio Mute Circuit: Short to Battery or Open) - sets when the RFA module detects an open or short to voltage on the mute circuit. If a short to voltage exists, the ACM does not enable the audio DSP module.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- RFA module
- ACM
PINPOINT TEST D: POOR QUALITY/DISTORTED/NO SOUND FROM ALL SPEAKERS - PREMIUM 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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D1 CHECK THE START SENSE SIGNAL TO THE ACM
- Ignition OFF.
- Disconnect: ACM C240a.
- Ignition ON.
- Measure the voltage between the ACM C240a-15, circuit CBP28 (GY/VT), harness side and ground.
- Is any voltage present?
Yes
GO to D2.
No
GO to D3.
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D2 CHECK THE START SENSE CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: RFA Module C2153d.
- Ignition ON.
- Measure the voltage between the ACM C240a-15, circuit CBP28 (GY/VT), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit. CLEAR any DTCs present. TEST the system for normal operation.
No
INSTALL a new RFA module. REFER to Multifunction Electronic Modules Remote Function Actuator (RFA) Module. TEST the system for normal operation.
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D3 CHECK THE START SENSE CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between the ACM C240a-15, circuit CBP28 (GY/VT), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to D4.
No
REPAIR the circuit. TEST the system for normal operation.
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D4 CHECK FOR CORRECT ACM OPERATION
- Ignition OFF.
- Disconnect all the ACM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all 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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