Pinpoint Test D: The Subwoofer Is Inoperative/Does Not Operate Correctly
Information and Entertainment System
Pinpoint Test D: The Subwoofer Is Inoperative/Does Not Operate Correctly
Refer to Wiring Diagram Set 130, Audio System for schematic and connector information. Diagrams By Number
Normal Operation
The subwoofer audio signals are sent from the audio unit to the subwoofer amplifier through circuits 167 (BN/OG) (BK at the subwoofer amplifier) and 168 (RD/BK) (GN at the subwoofer amplifier). The audio unit also sends a subwoofer enable signal to the subwoofer amplifier through circuit 173 (DG/VT) (WH at the subwoofer amplifier). The subwoofer is connected to the subwoofer amplifier through a pair of audio circuits.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Subwoofer amplifier
- Subwoofer speaker
- Audio unit
PINPOINT TEST D: THE SUBWOOFER IS INOPERATIVE/DOES NOT OPERATE CORRECTLY
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D1 CHECK THE SUBWOOFER AMPLIFIER VOLTAGE SUPPLY
- Ignition OFF.
- Disconnect: Subwoofer Amplifier C466a.
- Ignition ON.
- Measure the voltage between the subwoofer amplifier C466a-5, circuit 720 (YE), harness side and ground; and between the subwoofer amplifier C466a-6, circuit 720 (YE), harness side and ground.
- Are the voltages greater than 10 volts?
Yes
GO to D2.
No
REPAIR the circuit. TEST the system for normal operation.
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D2 CHECK THE SUBWOOFER GROUND CIRCUITS FOR CONTINUITY
- Ignition OFF.
- Measure the resistance between the subwoofer amplifier C466a-2, circuit 694 (RD), harness side and ground; and between the subwoofer amplifier C466a-3, circuit 694 (RD), harness side and ground.
- Are the resistances less than 5 ohms?
Yes
GO to D3.
No
REPAIR the circuit. TEST the system for normal operation.
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D3 CHECK FOR AN AUDIO SIGNAL FROM THE SUBWOOFER AMPLIFIER
- Connect: Subwoofer Amplifier C466a.
- Operate the audio system in radio tuner (AM/FM) mode.
- Measure the AC voltage by backprobing between the subwoofer amplifier C466b-3, circuit (BK), and the subwoofer amplifier C466b-4, circuit (BK/WH).
- Is a fluctuating AC voltage present?
Yes
INSTALL a new subwoofer speaker. REFER to Subwoofer Speaker Subwoofer Speaker. TEST the system for normal operation.
No
GO to D4.
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D4 CHECK THE SUBWOOFER AMPLIFIER ENABLE CIRCUIT VOLTAGE
- Ignition OFF.
- Disconnect: Subwoofer Amplifier C466a.
- Operate the audio system in radio tuner (AM/FM) mode.
- Measure the voltage between the subwoofer amplifier C466a-1, circuit 173 (WH), harness side and ground.
- Is the voltage between 3.8 and 6.7 volts?
Yes
GO to D7.
No
GO to D5.
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D5 CHECK THE SUBWOOFER AMPLIFIER ENABLE CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: Audio Unit C290c.
- Ignition ON.
- Measure the voltage between the subwoofer amplifier C466a-1, circuit 173 (WH), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit. TEST the system for normal operation.
No
GO to D6.
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D6 CHECK THE SUBWOOFER AMPLIFIER ENABLE CIRCUIT FOR AN OPEN OR SHORT TO GROUND
- Ignition OFF.
- Measure the voltage between the subwoofer amplifier C466a-1, circuit 173 (WH), harness side and the audio unit C290c-4, circuit 173 (DG/VT), harness side; and between the subwoofer amplifier C466a-1, circuit 173 (WH), harness side and ground.
- Is the resistance less than 5 ohms between the subwoofer amplifier and the audio unit, and greater than 10,000 ohms between the subwoofer amplifier and ground?
Yes
GO to D9.
No
REPAIR the circuit. TEST the system for normal operation.
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D7 CHECK THE AUDIO SIGNAL TO THE SUBWOOFER AMPLIFIER
- Operate the audio system in radio tuner (AM/FM) mode.
- Measure the voltage between the subwoofer amplifier C466a-7, circuit 167 (BK), harness side and the subwoofer amplifier C466a-8, circuit 168 (GN), harness side.
- Is a fluctuating AC voltage present?
Yes
INSTALL a new subwoofer amplifier. REFER to Subwoofer Amplifier Service and Repair. TEST the system for normal operation.
No
GO to D8.
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D8 CHECK THE AUDIO CIRCUITS TO THE SUBWOOFER AMPLIFIER FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: Audio Unit C290c.
- Measure the resistance between the subwoofer amplifier C466a-7, circuit 167 (BK), harness side and the audio unit C290c-1, circuit 167 (BN/OG), harness side; and between the subwoofer amplifier C466a-8, circuit 168 (GN), harness side and the audio unit C290c-2, circuit 168 (RD/BK) harness side.
- Are the resistances less than 5 ohms between the subwoofer amplifier and the audio unit, and greater than 10,000 ohms between the subwoofer amplifier and ground?
Yes
GO to D9.
No
REPAIR the circuit in question. TEST the system for normal operation.
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D9 CHECK FOR CORRECT AUDIO UNIT OPERATION
- Disconnect the audio unit connectors.
- Check for:
- corrosion
- pushed-out pins
- Connect the audio unit connectors and make sure they seat correctly.
- Operate the system and determine if the concern is still present.
- Is the concern still present?
Yes
REMOVE the audio unit. REFER to Audio Unit Service and Repair. SEND it to an authorized repair facility. TEST the system for normal operation after the repair.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.
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