Symptom Chart

WARNING: This page is about a different car, the 2006 Mercury Milan, 2006 Lincoln Zephyr, and 2006 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.

SYMPTOM CHART - AUDIO SYSTEM

Condition	Possible Sources	Action
No communication with the audio unit	Fuse Circuitry Audio unit	GO to PINPOINT TEST A .
The audio unit display is blank, but the audio unit operates	Audio unit	REMOVE the audio unit and SEND it to an authorized audio system repair facility. REFER to AUDIO UNIT - FUSION, MILAN or AUDIO UNIT - ZEPHYR . TEST the system for normal operation after the repair.
During CD mode, the audio unit displays: NO CD	No CD found	INSERT a known good CD. If the concern is still present, REMOVE the audio unit and SEND it to an authorized audio system repair facility. REMOVE the audio unit and SEND it to an authorized audio system repair facility. REFER to AUDIO UNIT - FUSION, MILAN or AUDIO UNIT - ZEPHYR . TEST the system for normal operation after the repair.
When the headlamp switch is in PARK or ON, there is no front audio unit backlighting, but all other backlighting functions are normal	Circuitry Audio unit	REFER to INSTRUMENT CLUSTER AND PANEL ILLUMINATION to continue diagnosis of the backlighting system.
The audio unit is inoperative	Fuse Circuitry Audio unit	GO to PINPOINT TEST A .
The steering wheel controls and the audio unit backlighting are inoperative, and the display shows a Ford logo on power-up (DTC B2477 may be present) - navigation only	Audio unit not configured correctly	RECONFIGURE the audio unit. REFER to MODULE CONFIGURATION . TEST the system for normal operation.
Poor reception	Circuitry Antenna Antenna cable Noise suppression equipment Antenna module Audio unit	GO to PINPOINT TEST B .
Continuous seek/scan in AM/FM	Circuitry Antenna Antenna cable Noise suppression equipment Antenna module Audio unit	GO to PINPOINT TEST B .
Poor quality/distorted/no sound from one or more of the speakers (not all speakers) - except THX® audio system	Door trim panel or watershield	INSPECT the plastic and metal trim panels for correct push-pin attachments, brittleness or damage. INSPECT the watershield for correct installation or damage. REPAIR as necessary. TEST the system for normal operation.
	Circuitry Speaker Audio unit	GO to PINPOINT TEST C .
Poor quality/distorted/no sound from one or more of the speakers (not all speakers) - THX® audio system	Door trim panel or watershield	INSPECT the plastic and metal trim panels for correct push-pin attachments, brittleness or damage. INSPECT the watershield for correct installation or damage. REPAIR as necessary. TEST the system for normal operation.
	Fuse Circuitry Speaker Subwoofer speaker Audio amplifier Digital signal processing (DSP) module Audio unit	GO to PINPOINT TEST D .
Poor quality/distorted/no sound from all speakers - except THX® audio system	Audio unit	With the key in RUN, MEASURE the voltage between the audio unit C290a-15, circuit CBP13 (GY/BN), harness side and ground. If voltage is present, REPAIR the circuit. TEST the system for normal operation. If no voltage is present, REMOVE the audio unit and SEND it to an authorized audio system repair facility. REFER to AUDIO UNIT - FUSION, MILAN or AUDIO UNIT - ZEPHYR . TEST the system for normal operation after the repair.
Poor quality/distorted/no sound from all speakers - THX® audio system	Fuse Circuitry DSP module Audio unit	GO to PINPOINT TEST E .
The subwoofer is inoperative/does not operate correctly - Audiophile	Fuse Circuitry Subwoofer speaker Subwoofer amplifier Audio unit	GO to PINPOINT TEST F .
The subwoofer is inoperative/does not operate correctly - THX® audio system	Fuse Circuitry Speaker Subwoofer speaker Audio amplifier DSP module Audio unit	GO to PINPOINT TEST D .
Loud popping sound when cycling the ignition	Fuse Circuitry Subwoofer amplifier (Audiophile) Audio amplifier (THX®) Audio unit	GO to PINPOINT TEST G .
The steering wheel controls are inoperative/do not operate correctly	Circuitry Clockspring Steering wheel controls Audio unit	GO to PINPOINT TEST H .

SYMPTOM CHART - NAVIGATION

Condition	Possible Sources	Action
Navigation system does not operate correctly - no global positioning system (GPS) antenna signal	GPS antenna Audio unit	GO to PINPOINT TEST I .
Navigation system does not operate correctly - the position cursor is inoperative	Audio unit	CHECK the anti-lock brake system (ABS) module for diagnostic trouble codes (DTCs). If ABS module DTCs are present, REFER to VEHICLE DYNAMIC SYSTEMS to continue diagnosis of the ABS module. If no ABS module DTCs are present, diagnose any audio unit DTCs. If the symptom is present after all audio unit DTCs are addressed, REMOVE the audio unit. REFER to AUDIO UNIT - ZEPHYR . SEND the audio unit to an authorized repair facility. TEST the system for normal operation after the repair.
Navigation system does not operate correctly - the audible switch feedback is inoperative	Audio unit	GO to PINPOINT TEST J .
Navigation system does not operate correctly - the voice guidance is inoperative/does not operate correctly	Circuitry Audio unit Digital signal processing (DSP) module	GO to PINPOINT TEST K .
Navigation system does not operate correctly - the display screen is inoperative	Audio unit	REMOVE the audio unit. REFER to AUDIO UNIT - ZEPHYR . SEND the audio unit to an authorized repair facility. TEST the system for normal operation after the repair.
Navigation system does not operate correctly - unable to insert or eject map disc	Audio unit	REMOVE the audio unit. REFER to AUDIO UNIT - ZEPHYR . SEND the audio unit to an authorized repair facility. TEST the system for normal operation after the repair.