Symptom Chart - Sound Quality

WARNING: This page is about a different car, the 2010 Lincoln MKX and 2010 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.

SOUND QUALITY SYMPTOM CHART

Condition	Possible Sources	Action
Poor reception - AM/FM	Wiring, terminals or connectors AM/FM antenna AM/FM antenna cable Charging system Ignition system Noise suppression equipment Audio Control Module (ACM)	GO to PINPOINT TEST A .
Poor reception - satellite radio	Obstructions to the antenna line of sight Satellite radio antenna Satellite radio antenna cable ACM (vehicles with navigation) Satellite Digital Audio Receiver System (SDARS) module (vehicles without navigation)	For vehicle without navigation, GO to PINPOINT TEST I . For vehicle with navigation, GO to PINPOINT TEST J .
Continuous seek/scan in AM/FM	No channel found in the selected category AM/FM antenna AM/FM antenna cable Noise suppression equipment ACM	GO to PINPOINT TEST A .
Continuous seek/scan - satellite radio	No channel found in the selected category Obstructions to the antenna line of sight Satellite radio antenna Satellite radio antenna cable ACM (vehicles with navigation) SDARS module (vehicles without navigation)	For vehicle without navigation, GO to PINPOINT TEST I . For vehicle with navigation, GO to PINPOINT TEST J .
Poor sound quality/no sound while in satellite radio mode - all other functions operate correctly	Satellite radio antenna Satellite radio antenna cable SDARS module (vehicles without navigation) ACM Accessory Protocol Interface Module (APIM) (vehicles with SYNC, without navigation)	For vehicle without navigation, GO to PINPOINT TEST I . For vehicle with navigation, GO to PINPOINT TEST J .
Poor quality/distorted/no sound from one or more speakers (not all speakers) - Base sound	Wiring, terminals or connectors Speaker ACM	GO to PINPOINT TEST B .
Poor quality/distorted/no sound from one or more speakers (not all speakers) - Premium sound without navigation	Wiring, terminals or connectors Speaker ACM	GO to PINPOINT TEST B .
Poor quality/distorted/no sound from one or more speakers (not all speakers) - Navigation without THX® sound	Fuse Wiring, terminals or connectors Speaker Audio amplifier ACM	GO to PINPOINT TEST K .
Poor quality/distorted/no sound from one or more speakers (not all speakers) - THX® audio system	Fuse Wiring, terminals or connectors Speaker Audio Digital Signal Processing (DSP) module ACM	GO to PINPOINT TEST C .
Poor quality/distorted/no sound from all speakers - all audio systems except THX®	Wiring, terminals or connectors ACM	GO to PINPOINT TEST L .
Poor quality/distorted/no sound from all speakers - THX® audio system	Fuse Wiring, terminals or connectors Audio DSP module ACM	GO to PINPOINT TEST D .
The subwoofer is inoperative/does not operate correctly - Premium sound	Fuse Wiring, terminals or connectors Subwoofer ACM	GO to PINPOINT TEST E .
The subwoofer is inoperative/does not operate correctly - THX® audio system	Wiring, terminals or connectors Subwoofer speaker Audio DSP module ACM	GO to PINPOINT TEST C .
Poor quality/distorted/no sound while in SYNC system mode - all other functions operate correctly	Wiring, terminals or connectors APIM ACM	GO to PINPOINT TEST X .