Diagnostic Routine AL
Diagnostic Routine AL
Diagnostic Overview
The LF Door Speaker Is Inoperative Or Has Poor Sound Quality
Refer to Wiring Diagram Set 130 for schematic and connector information Electrical Diagrams.
Normal Operation and Fault Conditions
The LF (Left Front) door speaker receives the audio signal from the audio amplifier. REFER to Audio Amplifier .
It may appear that the front speakers intermittently produce no sound due to volume settings or alerts present. Verify that the navigation voice and voice recognition volume settings are set high enough. Check for presence of SIRIUS(R) data services alerts, song alerts, incoming phone calls and parking aid sounder status before addressing a concern with the front speakers.
Pinpoint Test
1. CHECK THE LF (Left Front) AND RF (Right Front) DOOR SPEAKER OPERATION
1. Operate the audio system in radio tuner (AM/FM (Amplitude Modulation/Frequency Modulation)) mode.
2. Monitor the LF (Left Front) and RF (Right Front) door speaker.
Is only the LF (Left Front) door speaker inoperative?
2. CHECK THE AUDIO AMPLIFIER VOLTAGE SUPPLY CIRCUIT
1. Ignition OFF.
2. Disconnect: Audio Amplifier C3504A.
3. Ignition ON.
4. Measure:
Is the voltage greater than 11 volts?
3. CHECK THE AUDIO AMPLIFIER GROUND CIRCUIT
1. Measure:
Is the voltage greater than 11 volts?
4. CHECK THE AUDIO AMPLIFIER ENABLE CIRCUIT FOR VOLTAGE
1. Operate the audio system in radio tuner (AM/FM (Amplitude Modulation/Frequency Modulation)) mode.
2. Measure:
Is the voltage greater than 3.8 volts and less than 6.8 volts?
5. CHECK THE AUDIO AMPLIFIER ENABLE CIRCUIT FOR SHORT TO VOLTAGE
1. Ignition OFF.
2. Disconnect: ACM (Audio Control Module) C240B.
3. Measure:
Is the any voltage present?
6. CHECK THE AUDIO AMPLIFIER ENABLE CIRCUIT FOR A SHORT TO GROUND
1. Ignition OFF.
2. Disconnect: ACM (Audio Control Module) C240B.
3. Measure:
Is the resistance greater than 10,000 ohms?
7. CHECK THE AUDIO AMPLIFIER ENABLE CIRCUIT FOR AN OPEN
1. Measure:
Is the resistance less than 3 ohms?
8. CHECK THE AUDIO SIGNAL TO THE LF (Left Front) DOOR SPEAKER
1. Ignition OFF.
2. Disconnect: LF (Left Front) Door Speaker.
3. Operate the audio system in radio tuner (AM/FM (Amplitude Modulation/Frequency Modulation)) mode.
4. Measure:
Is a fluctuating AC (Alternating Current) voltage present?
9. CHECK THE AUDIO CIRCUITS TO THE LF (Left Front) DOOR SPEAKER FOR A SHORT TO VOLTAGE
1. Ignition OFF.
2. Disconnect: Audio Amplifier C3504B.
3. Ignition ON.
4. Measure:
Is any voltage present?
10. CHECK THE AUDIO CIRCUITS TO THE LF (Left Front) DOOR SPEAKER FOR A SHORT TO GROUND
1. Ignition OFF.
2. Measure:
Are the resistances greater than 10,000 ohms?
11. CHECK THE AUDIO CIRCUITS TO THE LF (Left Front) DOOR SPEAKER FOR AN OPEN
1. Measure:
Are the resistances less than 3 ohms?
12. CHECK THE AUDIO SIGNAL TO THE AUDIO AMPLIFIER
1. Ignition OFF.
2. Disconnect: Audio Amplifier C3504A.
3. Operate the audio system in radio tuner (AM/FM (Amplitude Modulation/Frequency Modulation)) mode.
4. Measure:
Is a fluctuating AC (Alternating Current) voltage present?
13. CHECK THE AUDIO CIRCUITS TO THE AUDIO AMPLIFIER FOR A SHORT TO VOLTAGE
1. Ignition OFF.
2. Disconnect: ACM (Audio Control Module) C240A.
3. Ignition ON.
4. Measure:
Is any voltage present?
14. CHECK THE AUDIO CIRCUITS TO THE AUDIO AMPLIFIER FOR A SHORT TO GROUND
1. Ignition OFF.
2. Measure:
Are the resistances greater than 10,000 ohms?
15. CHECK THE AUDIO CIRCUITS TO THE AUDIO AMPLIFIER FOR AN OPEN
1. Measure:
Are the resistances less than 3 ohms?
16. CHECK FOR CORRECT ACM (Audio Control Module) OPERATION
1. Disconnect and inspect all ACM (Audio Control Module) connectors.
2. Repair:
- corrosion (install new connector or terminals- clean module pins)
- damaged pins - install new terminals/pins
- pushed-out pins - install new pins as necessary
3. Reconnect the ACM (Audio Control Module) connectors. Make sure they seat and latch correctly.
4. Operate the system and determine if the concern is still present.
Is the concern still present?
