Pinpoint Test B: Poor Quality/Distorted/No Sound From One Or More Speakers (Not All Speakers) - Vehicles Without Navigation
Information and Entertainment System
Pinpoint Tests
Pinpoint Test B: Poor Quality/Distorted/No Sound From One Or More Speakers (Not All Speakers) - Vehicles Without Navigation
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 in the form of an AC voltage. The ACM provides internal circuit protection for shorts to ground or shorts to voltage.
If the vehicle is equipped with the family entertainment system, the rear channel audio signals from the ACM route to the Rear Entertainment Module (RETM), then to the speakers. In dual-play mode, the RETM mutes the rear speaker output. Make sure the audio system is in single-play mode before diagnosing a rear speaker concern.
A short to ground or short to voltage in the circuitry to one of the speakers may cause multiple speakers to lose sound due to the built-in overload protection feature of the ACM. In this case, a speaker fault DTC sets, and this pinpoint test should be followed to isolate the damaged circuit.
- DTC B2965 (Audio System Speaker Circuit Fault) - sets when an open, short to ground, or short to voltage is detected on any of the speaker circuits. If the ACM activates the built-in overload protection, DTC B1342 may also be set. The cause of DTC B2965 must be repaired before DTC B1342 can be cleared.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Speaker
- ACM
- RETM (if equipped)
PINPOINT TEST B: POOR QUALITY/DISTORTED/NO SOUND FROM ONE OR MORE SPEAKERS (NOT ALL SPEAKERS) - VEHICLES WITHOUT NAVIGATION
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
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B1 ISOLATE THE SUSPECT SPEAKER
NOTE: Only Crew Cab with Audiophile has rear tweeter speakers.
- Enter the following diagnostic mode on the scan tool: Speaker Walkaround Test.
- Carry-out the speaker walkaround test.
- Is the concern with a rear tweeter speaker only?
Yes
GO to B8.
No
GO to B2.
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B2 CHECK THE AUDIO SIGNALS TO THE SUSPECT SPEAKER
- Ignition OFF.
- Disconnect: Suspect Speaker.
- Operate the audio system in radio tuner (AM/FM), single-play 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
If the vehicle is equipped with the family entertainment system and the concern is with a rear speaker, GO to B3.
Otherwise, GO to B6.
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B3 CHECK THE AUDIO SIGNALS TO THE RETM
- Ignition OFF.
- Disconnect: RETM C949.
- Operate the audio system in radio tuner (AM/FM), single-play mode.
- Measure the AC voltage between the RETM C949-11, circuit VME12 (BN/WH), harness side and the RETM C949-12, circuit RME12 (BN/BU), harness side.
- Measure the AC voltage between the RETM C949-27, circuit VME09 (WH/GN), harness side and the RETM C949-28, circuit RME09 (BN/YE), harness side.
- Is a fluctuating AC voltage present?
Yes
GO to B6.
No
GO to B4.
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B4 CHECK THE AUDIO CIRCUITS TO THE RETM 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 B5.
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B5 CHECK THE AUDIO CIRCUITS TO THE RETM FOR AN OPEN OR SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between the RETM, harness side and the ACM, harness side; and between the RETM, harness side and ground as follows:
- Are the resistances less than 5 ohms between the RETM and the ACM, and greater than 10,000 ohms between the RETM and ground?
Yes
GO to B11.
No
REPAIR the circuit in question. CLEAR any DTCs present. TEST the system for normal operation.
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B6 CHECK THE CIRCUITS TO THE SUSPECT SPEAKER FOR A SHORT TO VOLTAGE
- Ignition OFF.
- 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 B7.
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B7 CHECK THE CIRCUITS TO THE SUSPECT SPEAKER FOR AN OPEN OR SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between the suspect speaker, harness side and the ACM (or 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 ACM (or RETM if equipped with the family entertainment system), and greater than 10,000 ohms between the suspect speaker and ground?
Yes
REPAIR the circuit in question. CLEAR any DTCs present. TEST the system for normal operation.
No
If the vehicle is equipped with the family entertainment system, GO to B12.
Otherwise, GO to B11.
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B8 CHECK FOR VOLTAGE TO THE SUSPECT TWEETER SPEAKER
- Ignition OFF.
- Disconnect: Suspect Tweeter Speaker.
- Operate the audio system in radio tuner (AM/FM) mode.
- Measure the AC voltage between the suspect tweeter speaker pin 1 and pin 2, harness side as follows:
- Is a fluctuating AC voltage present?
Yes
INSTALL a new speaker for the inoperative tweeter speaker. REFER to Door Speaker Door Speaker. CLEAR any DTCs present. TEST the system for normal operation.
No
GO to B9.
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B9 CHECK THE CIRCUITS TO THE SUSPECT TWEETER SPEAKER FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: LR Speaker C395b (LH Speaker Concern) or RR Speaker C396b (RH Speaker Concern).
- Ignition ON.
- Measure the voltage between the suspect tweeter 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 B10.
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B10 CHECK THE CIRCUITS TO THE SUSPECT TWEETER SPEAKER CIRCUITS FOR AN OPEN OR SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between the suspect tweeter speaker, harness side and the respective door speaker, harness side; and between the suspect tweeter speaker, harness side and ground as follows:
- Is the resistance less than 5 ohms between the suspect tweeter speaker and the door speaker, and greater than 10,000 ohms between the suspect tweeter speaker and ground?
Yes
INSTALL a new door speaker. REFER to Door Speaker Door Speaker. CLEAR any DTCs present. TEST the system for normal operation.
No
REPAIR the circuit in question. CLEAR any DTCs present. TEST the system for normal operation.
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B11 CHECK FOR CORRECT ACM OPERATION
- Ignition OFF.
- 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 any DTCs present.
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B12 CHECK FOR CORRECT RETM OPERATION
- Ignition OFF.
- 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. CLEAR any ACM DTCs present. 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 any ACM DTCs present.
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