Pinpoint Test AA: Poor Quality/Distorted/No Sound While In SYNC(R) Mode
Information and Entertainment System
Pinpoint Test AA: Poor Quality/Distorted/No Sound While In SYNC(R) Mode
Refer to Wiring Diagrams Set 130, Audio System/Navigation for schematic and connector information. Electrical Diagrams
Normal Operation
The Accessory Protocol Interface Module (APIM) transmits left and right channel analog audio signals. These signals include inputs from the Universal Serial Bus (USB) port, the audio input jack, and a Bluetooth media device.
If the vehicle is equipped with the family entertainment system, these audio signals are sent to the Rear Entertainment Module (RETM), then to the Audio Control Module (ACM). For vehicles without the family entertainment system, the audio signals are sent directly to the ACM (Audio Control Module).
If a USB (Universal Serial Bus) mass storage device is used to play an audio file, the SYNC(R) system only plays audio files that do not have Digital Rights Management (DRM) protection.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- RETM (Rear Entertainment Module) (if equipped)
- APIM (Accessory Protocol Interface Module)
- ACM (Audio Control Module)
PINPOINT TEST AA : POOR QUALITY/DISTORTED/NO SOUND WHILE IN SYNC(R) MODE
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
AA1 VERIFY THE OPERATION OF THE SYNC(R) SYSTEM AUDIO SOURCES
- Connect: Multi-Media Interface Tester.
- Using the Multi-Media Interface Tester, test the audio output for the audio input jack, USB (Universal Serial Bus) port, and Bluetooth.
Is there poor quality/distorted sound from each SYNC(R) audio source?
Yes
If the vehicle is equipped with the family entertainment system, GO to AA2.
Otherwise, GO to AA3.
No
If the concern is only with some (but not all) of the audio sources, GO to Symptom Chart - SYNC System to diagnose the observed symptom. Symptom Chart - SYNC(R) System
If all audio sources operate correctly, the concern is with the customer device.
AA2 VERIFY THE OPERATION OF THE FAMILY ENTERTAINMENT SYSTEM AUDIO
- NOTE: Make sure a known good DVD is inserted in the LH DVD player before carrying out this step.
Operate the audio system in single-play (no headphone icon in the ACM (Audio Control Module)) DVD mode and make sure the LH DVD player is selected.
- Observe the audio output.
Is there poor quality/distorted sound while in DVD mode?
Yes
GO to Pinpoint Test P. Pinpoint Test P: Poor Quality/Distorted Audio-Video/No Sound While in Family Entertainment Mode - All Other Functions Operate
No
GO to AA3.
AA3 CHECK THE AUDIO CIRCUITS FROM THE APIM (Accessory Protocol Interface Module) FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: ACM (Audio Control Module) C240C (Vehicles Without Family Entertainment System).
- Disconnect: RETM (Rear Entertainment Module) C2949B (Vehicles With Family Entertainment System).
- Disconnect: APIM (Accessory Protocol Interface Module) C3342.
- Measure the voltage between the APIM (Accessory Protocol Interface Module), harness side and ground as follows:
Positive Meter Lead Negative Meter Lead C3342-23 VME53 (VT/GN) Ground C3342-24 RME53 (BN/WH) Ground C3342-25 VME52 (BU) Ground C3342-26 RME52 (GY/OG) Ground
Is any voltage present?
Yes
REPAIR the circuit in question. TEST the system for normal operation.
No
GO to AA4.
AA4 CHECK THE AUDIO CIRCUITS FROM THE APIM (Accessory Protocol Interface Module) FOR AN OPEN OR SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between the APIM (Accessory Protocol Interface Module), harness side, and the ACM (Audio Control Module) (vehicles without family entertainment system) or RETM (Rear Entertainment Module) (vehicles with family entertainment system), harness side; and between the APIM (Accessory Protocol Interface Module), harness side and ground as follows:
Positive Meter Lead Negative Meter Lead Circuit C3342-23 C240C-9 or C2949B-10, then ground VME53 (VT/GN) C3342-24 C240C-10 or C2949B-23, then ground RME53 (BN/WH) C3342-25 C240C-1 or C2949B-24, then ground VME52 (BU) C3342-26 C240C-2 or C2949B-11, then ground RME52 (GY/OG)
Is the resistance less than 5 ohms between the APIM (Accessory Protocol Interface Module) and the ACM (Audio Control Module) (or RETM (Rear Entertainment Module)), and greater than 10,000 ohms between the APIM (Accessory Protocol Interface Module) and ground?
Yes
REPAIR the circuit in question. TEST the system for normal operation.
No
GO to AA5.
AA5 CHECK FOR CORRECT APIM (Accessory Protocol Interface Module) OPERATION
- Connect: All Disconnected Connectors.
- Disconnect the APIM (Accessory Protocol Interface Module) connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the APIM (Accessory Protocol Interface Module) connector and make sure it seats correctly.
- Wait 2 minutes for the APIM (Accessory Protocol Interface Module) to re-initialize.
- Operate the system and verify the concern is still present.
Is the concern still present?
Yes
INSTALL a new APIM (Accessory Protocol Interface Module). REFER to Accessory Protocol Interface Module (APIM) . TEST the system for normal operation.
If the concern is still present and the vehicle is equipped with the family entertainment system, GO to AA6.
If the concern is still present and the vehicle is not equipped with the family entertainment system, GO to AA7.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
AA6 CHECK FOR CORRECT RETM (Rear Entertainment Module) OPERATION
- Disconnect the RETM (Rear Entertainment Module) connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the RETM (Rear Entertainment Module) connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
Is the concern still present?
Yes
INSTALL a new RETM (Rear Entertainment Module). REFER to Rear Entertainment Module (RETM) . TEST the system for normal operation.
If the concern is still present, GO to AA7.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
AA7 CHECK FOR CORRECT ACM (Audio Control Module) OPERATION
- Disconnect all the ACM (Audio Control Module) connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the ACM (Audio Control Module) connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
Is the concern still present?
Yes
INSTALL a new ACM (Audio Control Module). REFER to 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.