Pinpoint Test I: Poor Quality/Distorted/No Sound - Family Entertainment System
Information and Entertainment System
Pinpoint Tests
Pinpoint Test I: Poor Quality/Distorted/No Sound - Family Entertainment System
Refer to Wiring Diagram Set 130, Audio System/Navigation for schematic and connector information. Diagrams By Number
Normal Operation
The Rear Entertainment Module (RETM) routes audio signals to the Audio Control Module (ACM). In single-play mode, the ACM plays the DVD audio on all speakers. In dual-play mode, the audio to the rear speakers is muted and the RETM continues to control the rear audio source to the headphones.
The audio signals from the Satellite Digital Audio Receiver System (SDARS) module (vehicles without navigation) and the Accessory Protocol Interface Module (APIM) (if equipped) route through the RETM to the ACM. This allows for single-play and dual-play mode to include satellite radio and SYNC audio sources.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- RETM
- ACM
PINPOINT TEST I: POOR QUALITY/DISTORTED/NO SOUND - FAMILY ENTERTAINMENT SYSTEM
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTE: Before diagnosing the family entertainment system, make sure a known good DVD is installed.
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I1 CHECK THE OPERATION OF THE DVD VIDEO
- Operate the DVD entertainment system in single-play mode. Refer to the Owner's Literature.
- Does the DVD video operate correctly?
Yes
GO to I2.
No
GO to Pinpoint Test U. Pinpoint Test U: The Family Entertainment System Is Inoperative/Does Not Operate Correctly
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I2 CHECK THE RETM AUDIO PASS-THROUGH
NOTE: If the vehicle is equipped with both the SYNC system and satellite radio (but not navigation), either of the next 2 steps can be followed.
- For vehicles equipped with the SYNC system, connect the Multi-Media Interface Tester, and operate the audio system in SYNC mode. Refer to the tool instructions.
- For vehicles equipped with satellite radio (but not navigation), operate the audio system in satellite radio mode
- Observe the audio output.
- Does the SYNC system (or satellite radio) audio operate correctly?
Yes
GO to I5.
No
GO to I3.
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I3 CHECK THE AUDIO CIRCUITS TO THE ACM FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: ACM C240c.
- Disconnect: RETM C949.
- Ignition ON.
- Measure the voltage between the ACM, harness side and ground as follows:
- Is any voltage present?
Yes
REPAIR the circuit in question. TEST the system for normal operation.
No
GO to I4.
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I4 CHECK THE AUDIO CIRCUITS TO THE ACM 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 I5.
No
REPAIR the circuit in question. TEST the system for normal operation.
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I5 CHECK FOR CORRECT RETM OPERATION
- Connect: ACM C240c.
- Disconnect the RETM connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the RETM connector and make sure it seats correctly.
- 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.
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