Pinpoint Test D: The Subwoofer Is Inoperative

Information and Entertainment System

Pinpoint Test D: The Subwoofer Is Inoperative

Refer to Wiring Diagram Set 130, Audio System for schematic and connector information. Diagrams By Number

Normal Operation

Audio signals are sent from the audio unit to the subwoofer amplifier, then to the subwoofer. An enable/clip circuit carries out 2 functions: to turn the subwoofer amplifier on, and to monitor an overload condition to the subwoofer amplifier. In the event of an overload, the audio unit clips the audio output signal to the subwoofer amplifier (heard as distortion).

- DTC B2913 (Audio Subwoofer Not Connected) - sets when the audio unit does not detect the subwoofer amplifier through the enable circuit. A fault in any of the possible causes listed below could cause this DTC to set.

This pinpoint test is intended to diagnose the following:

- Fuse
- Wiring, terminals or connectors
- Subwoofer amplifier
- Audio unit

PINPOINT TEST D: THE SUBWOOFER IS INOPERATIVE

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery, Mounting and Cables Battery Disconnect.

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D1 CHECK THE SUBWOOFER AMPLIFIER VOLTAGE SUPPLY CIRCUIT FOR AN OPEN

- Ignition OFF.
- Disconnect: Subwoofer Amplifier C466.
- Measure the voltage between the subwoofer amplifier C466-5, circuit 720 (RD/YE), harness side and ground.

- Is the voltage greater than 10 volts?

Yes
GO to D2.

No
VERIFY the Battery Junction Box (BJB) fuse 12 (20A) is OK. If OK, REPAIR the circuit. CLEAR the DTCs. TEST the system for normal operation. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. Diagrams By Number

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D2 CHECK THE SUBWOOFER GROUND CIRCUIT FOR CONTINUITY

- Disconnect: Negative Battery Cable.
- Measure the resistance between the subwoofer amplifier C466-3, circuit 694 (BK/GN), harness side and ground.

- Is the resistance less than 5 ohms?

Yes
GO to D3.

No
REPAIR the circuit. CLEAR the DTCs. TEST the system for normal operation.

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D3 CHECK THE SUBWOOFER AMPLIFIER ENABLE CIRCUIT FOR CORRECT VOLTAGE

- Connect: Negative Battery Cable.
- Ignition ON.
- Operate the audio system in radio tuner (AM/FM) mode.
- Measure the voltage between the subwoofer amplifier C466-1, circuit 173 (DG/VT), harness side and ground.

- Is the voltage between 3.8 and 6.7 volts?

Yes
GO to D6.

No
GO to D4.

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D4 CHECK THE SUBWOOFER AMPLIFIER ENABLE CIRCUIT FOR A SHORT TO VOLTAGE

- Ignition OFF.
- Disconnect: Audio Unit C290b.
- Ignition ON.
- Measure the voltage between the subwoofer amplifier C466-1, circuit 173 (DG/VT), harness side and ground.

- Is any voltage present?

Yes
REPAIR the circuit. CLEAR the DTCs. TEST the system for normal operation.

No
GO to D5.

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D5 CHECK THE SUBWOOFER AMPLIFIER ENABLE CIRCUIT FOR AN OPEN OR SHORT TO GROUND

- Ignition OFF.
- Measure the resistance between the subwoofer amplifier C466-1, circuit 173 (DG/VT), harness side and the audio unit C290b-4, circuit 173 (DG/VT), harness side; and between the subwoofer amplifier C466-1, circuit 173 (DG/VT), 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
INSTALL a new audio unit. REFER to Audio Unit Service and Repair. TEST the system for normal operation.

No
REPAIR the circuit. CLEAR the DTCs. TEST the system for normal operation.

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D6 CHECK THE AUDIO SIGNAL TO THE SUBWOOFER AMPLIFIER

- Operate the audio unit in radio tuner (AM/FM) mode.
- Measure the AC voltage between the subwoofer amplifier C466-7, circuit 167 (BN/OG), harness side and the subwoofer amplifier C466-8, circuit 168 (RD/BK), harness side.

- Is a fluctuating AC voltage present?

Yes
INSTALL a new subwoofer amplifier. REFER to Subwoofer Amplifier Service and Repair. CLEAR the DTCs. TEST the system for normal operation.

No
GO to D7.

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D7 CHECK THE SUBWOOFER AUDIO CIRCUITS FOR A SHORT TO VOLTAGE

- Ignition OFF.
- Disconnect: Audio Unit C290b.
- Ignition ON.
- Measure the voltage between the subwoofer amplifier C466-7, circuit 167 (BN/OG), harness side and ground; and between the subwoofer amplifier C466-8, circuit 168 (RD/BK), harness side and ground.

- Is any voltage present?

Yes
REPAIR the circuit in question. CLEAR the DTCs. TEST the system for normal operation.

No
GO to D8.

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D8 CHECK THE SUBWOOFER AUDIO CIRCUITS FOR AN OPEN OR SHORT TO GROUND

- Ignition OFF.
- Measure the resistance between the subwoofer amplifier, harness side and the audio unit, harness side; and between the subwoofer amplifier, harness side and ground as follows: