Diagnostic Routine C
Diagnostic Routine C
Diagnostic Overview
No Sound From All Speakers
Refer to Wiring Diagram Set 130 for schematic and connector information Electrical Diagrams.
Normal Operation and Fault Conditions
When the key is in START, the ACM (Audio Control Module) receives voltage on the START signal circuit. The ACM (Audio Control Module) then mutes the speaker output to prevent voltage spikes from producing a popping noise through the speakers. However, a short to voltage on this circuit causes the ACM (Audio Control Module) output to be continuously muted.
The audio DSP (Digital Signal Processing) module is enabled through software. Additionally, the ACM (Audio Control Module) can mute the audio DSP (Digital Signal Processing) module through the mute/unmute circuit. If the audio DSP (Digital Signal Processing) module detects less than 3.5 volts on the mute/unmute circuit, it mutes the speaker output. As a result, an open or short to ground in the mute/unmute circuit causes the audio system to produce no sound, because the enable signal does not reach the audio DSP (Digital Signal Processing) module. In the event of an overload, the audio DSP (Digital Signal Processing) module clips the audio output signal to the speakers and subwoofer (heard as distortion) in order to prevent damage to the speakers. If a speaker circuit fault DTC (Diagnostic Trouble Code) is present, REFER to DTC Chart: Audio Digital Signal Processing (DSP) Module - Sony Sound DTC Chart: Audio Digital Signal Processing (DSP) Module - Sony Sound.
Pinpoint Test
1. CHECK THE START SENSE CIRCUIT FOR A SHORT TO VOLTAGE
1. Ignition OFF.
2. Disconnect: ACM (Audio Control Module) C240A.
3. Ignition ON.
4. Measure:
Is any voltage present?
2. CHECK THE AUDIO DSP (Digital Signal Processing) MODULE VOLTAGE SUPPLY
1. Ignition OFF.
2. Disconnect: Audio DSP (Digital Signal Processing) Module C3154C.
3. Ignition ON.
4. Measure:
Are the voltages greater than 11 volts?
3. CHECK THE AUDIO DSP (Digital Signal Processing) MODULE GROUND CIRCUITS
1. Measure:
Are the voltages greater than 11 volts?
4. CHECK THE AUDIO DSP (Digital Signal Processing) MODULE ENABLE CIRCUIT FOR CORRECT VOLTAGE
1. Ignition OFF.
2. Disconnect: Audio DSP (Digital Signal Processing) Module C3154A.
3. Ignition ON.
4. Operate the audio system in radio tuner (AM/FM (Amplitude Modulation/Frequency Modulation)) mode.
5. Measure:
Is the voltage between 3.5 and 5 volts?
5. CHECK THE AUDIO DSP (Digital Signal Processing) MODULE ENABLE CIRCUIT FOR A SHORT TO VOLTAGE
1. Ignition OFF.
2. Disconnect: ACM (Audio Control Module) C240B.
3. Ignition ON.
4. Measure:
Is any voltage present?
6. CHECK THE AUDIO DSP (Digital Signal Processing) MODULE ENABLE CIRCUIT FOR A SHORT TO GROUND
1. Ignition OFF.
2. Measure:
Is the resistance greater than 10,000 ohms?
7. CHECK THE AUDIO DSP (Digital Signal Processing) MODULE ENABLE CIRCUIT FOR AN OPEN
1. Measure:
Is the resistance less than 3 ohms?
8. CHECK FOR CORRECT ACM (Audio Control Module) OPERATION
1. Ignition OFF.
2. Disconnect and inspect all ACM (Audio Control Module) connectors.
3. Repair:
- corrosion (install new connectors or terminals - clean module pins)
- damaged or bent pins - install new terminals pins
- pushed-out pins - install new pins as necessary
4. Reconnect the ACM (Audio Control Module) connectors. Make sure they seat and latch correctly.
5. Operate the system and determine if the concern is still present.
Is the concern still present?
9. CHECK FOR CORRECT AUDIO DSP (Digital Signal Processing) MODULE OPERATION
1. Ignition OFF.
2. Disconnect and inspect all audio DSP (Digital Signal Processing) module connectors.
3. Repair:
- corrosion (install new connectors or terminals - clean module pins)
- damaged or bent pins - install new terminals pins
- pushed-out pins - install new pins as necessary
4. Reconnect the audio DSP (Digital Signal Processing) module connectors. Make sure they seat and latch correctly.
5. Operate the system and determine if the concern is still present.
Is the concern still present?
