Pinpoint Test B: Poor Quality/Distorted/No Sound From One Or More Speakers (Not All Speakers)
Information and Entertainment System
Pinpoint Tests
Pinpoint Test B: Poor Quality/Distorted/No Sound from One or More Speakers (Not All Speakers)
Refer to Wiring Diagram Set 130, Audio System/Navigation for schematic and connector information. Diagrams By Number
Normal Operation
The Audio Control Module (ACM) directs audio signals to the speakers and to the Rear Entertainment Module (RETM) (if equipped) in the form of a fluctuating AC voltage. The rear door speakers receive audio signals through the RETM (if equipped) or directly from the ACM.
If the vehicle is equipped with a DVD entertainment system, the RETM mutes the speaker output to the rear speakers when the audio system is in dual-play mode. Make sure the audio system is in single-play mode before diagnosing a symptom of no sound to the rear speakers.
For the navigation system, if the voice guidance setting is set to zero rather than to off, it may appear that the front speakers intermittently produce no sound. Make sure the voice guidance setting is not set to zero before addressing a concern with the front speakers.
- DTC B2965 (Audio System Speaker Circuit Fault) - sets when an open, a short to ground, or a short to voltage is detected on the front door or rear door speaker circuits. The ACM checks for faults once every 500ms during normal operation. The following should also be noted:
- The Audiophile ACM does not check for opens in the front door speakers.
- The navigation ACM does not check for opens.
For some audio systems, a short to ground or short to voltage in the circuitry to one of the speakers can cause all speakers to lose sound due to the built-in overload protection feature of the ACM. In this case, DTC B2965 sets in the ACM, and this pinpoint test should be followed to isolate the damaged circuit.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Speaker
- RETM (if equipped)
- ACM
PINPOINT TEST B: POOR QUALITY/DISTORTED SOUND OR NO SOUND FROM ONE OR MORE SPEAKERS (NOT ALL SPEAKERS)
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTE: Make sure the audio system is in single-play mode before beginning this pinpoint test, or the results will not be accurate.
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B1 CHECK THE SPEAKER CIRCUITS FOR VOLTAGE
- Ignition OFF.
- Disconnect: Suspect Speaker.
- Operate the audio system in radio tuner (AM/FM) mode.
- Measure the AC voltage between the suspect speaker pin 1 and pin 2, harness side as follows:
- Is a fluctuating AC voltage present?
Yes
INSTALL a new speaker for the suspect speaker. REFER to Door Speaker Door Speaker. CLEAR any DTCs present. TEST the system for normal operation.
No
For a front speaker concern, GO to B10.
For a rear speaker concern, GO to B2.
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B2 VERIFY THE PRESENCE OF A DVD ENTERTAINMENT SYSTEM
- Ignition OFF.
- Check for the presence of a DVD entertainment system.
- Is the vehicle equipped with a DVD entertainment system?
Yes
GO to B5.
No
GO to B3.
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B3 CHECK THE REAR SPEAKER CIRCUITS FOR A SHORT TO VOLTAGE
- Disconnect: ACM C240a.
- Ignition ON.
- Measure the voltage between the suspect speaker pins, harness side and ground as follows:
- Is any voltage present?
Yes
REPAIR the circuit in question. CLEAR any DTCs present. TEST the system for normal operation.
No
GO to B4.
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B4 CHECK THE REAR SPEAKER CIRCUITS FOR AN OPEN OR SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between the suspect speaker, harness side and the ACM, harness side; and between the suspect speaker, harness side and ground as follows:
- Is the resistance less than 5 ohms between the suspect speaker and the ACM, and greater than 10,000 ohms between the suspect speaker and ground?
Yes
GO to B12.
No
REPAIR the circuit in question. CLEAR any DTCs present. TEST the system for normal operation.
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B5 CHECK THE ACM OUTPUT SIGNALS
- Disconnect: RETM C9029.
- Operate the audio system in radio tuner (AM/FM) mode.
- Measure the AC voltage between the RETM pins, harness side as follows:
- Is a fluctuating AC voltage present?
Yes
GO to B8.
No
GO to B6.
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B6 CHECK THE ACM OUTPUT CIRCUITS FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: ACM C240a.
- Ignition ON.
- Measure the voltage between the RETM, harness side and ground as follows:
- Is any voltage present?
Yes
REPAIR the circuit in question. CLEAR any DTCs present. TEST the system for normal operation.
No
GO to B7.
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B7 CHECK THE ACM OUTPUT CIRCUITS FOR AN OPEN OR SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between the ACM, harness side and the RETM, harness side; and between the ACM, harness side and ground as follows:
- Is the resistance less than 5 ohms between the ACM and the RETM, and greater than 10,000 ohms between the ACM and ground?
Yes
GO to B12.
No
REPAIR the circuit in question. CLEAR any DTCs present. TEST the system for normal operation.
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B8 CHECK THE RETM OUTPUT CIRCUITS FOR A SHORT TO VOLTAGE
- Disconnect: Suspect Speaker.
- Ignition ON.
- Measure the voltage between the suspect speaker pins, harness side and ground as follows:
- Is any voltage present?
Yes
REPAIR the circuit in question. CLEAR any DTCs present. TEST the system for normal operation.
No
GO to B9.
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B9 CHECK THE RETM OUTPUT CIRCUITS FOR AN OPEN OR SHORT TO GROUND
- Measure the resistance between the suspect speaker, harness side and the RETM, harness side; and between the suspect speaker, harness side and ground as follows:
- Is the resistance less than 5 ohms between the suspect speaker and the RETM, and greater than 10,000 ohms between the suspect speaker and ground?
Yes
GO to B13.
No
REPAIR the circuit in question. CLEAR any DTCs present. TEST the system for normal operation.
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B10 CHECK THE FRONT SPEAKER CIRCUITS FOR A SHORT TO VOLTAGE
- Disconnect: ACM C240a.
- Ignition ON.
- Measure the voltage between the suspect speaker, harness side and ground as follows:
- Is any voltage present?
Yes
REPAIR the circuit in question. CLEAR any DTCs present. TEST the system for normal operation.
No
GO to B11.
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B11 CHECK THE FRONT SPEAKER CIRCUITS FOR AN OPEN OR SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between the ACM, harness side and the suspect speaker, harness side; and between the ACM, harness side and ground as follows:
- Is the resistance less than 5 ohms between the ACM and the suspect speaker, and greater than 10,000 ohms between the ACM and ground
Yes
GO to B12.
No
REPAIR the circuit in question. CLEAR any DTC present. TEST the system for normal operation.
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B12 CHECK FOR CORRECT ACM OPERATION
- Connect: All Disconnected Connectors.
- Disconnect all the ACM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the ACM connectors and make sure they seat correctly.
- Operate the system and determine if the concern is still present.
- Is the concern still present?
Yes
INSTALL a new ACM. REFER to Audio Control Module (ACM) Audio Control Module (ACM). TEST the system for normal operation.
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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B13 CHECK FOR CORRECT RETM OPERATION
- Connect: All Disconnected Connectors.
- Disconnect the RETM connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the RETM connector and make sure it seats correctly.
- Operate the system and determine if the concern is still present.
- Is the concern still present?
Yes
INSTALL a new RETM. REFER to Rear Entertainment Module (RETM) Service and Repair. TEST the system for normal operation.
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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