Pinpoint Test S: Poor Quality/Distorted/No Sound While In SYNC(R) Mode
Information and Entertainment System
Pinpoint Test S: Poor Quality/Distorted/No Sound While In SYNC(R) Mode
Normal Operation
The Accessory Protocol Interface Module (APIM) sends left and right channel analog audio signals to the Audio Front Control Module (ACM). The signals include inputs from the Universal Serial Bus (USB) port, the audio input jack, and a Bluetooth media device.
If supported by the user device, the USB (Universal Serial Bus) can provide charging. Because of this feature, when a USB (Universal Serial Bus) device is plugged into the USB (Universal Serial Bus) port, the SYNC(R) system does not automatically switch to the device.
It is important to note that when 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 is normal operation.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- APIM (Accessory Protocol Interface Module)
- ACM (Audio Front Control Module)
PINPOINT TEST S : 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.
S1 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 connection.
Is there poor quality/distorted sound from each SYNC(R) audio source?
Yes
GO to S2.
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.
S2 CHECK THE AUDIO CIRCUITS FROM THE APIM (Accessory Protocol Interface Module) FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: ACM (Audio Front Control Module) C240B.
- Disconnect: APIM (Accessory Protocol Interface Module) C2383.
- Measure the voltage between the APIM (Accessory Protocol Interface Module), harness side and ground as follows:
Positive Meter Lead Negative Meter Lead C2383-23 VME53 (VT/GN) Ground C2383-24 RME53 (BN/WH) Ground C2383-25 VME52 (BU) Ground C2383-26 RME52 (GY/OG) Ground
Is any voltage present?
Yes
REPAIR the circuit in question. TEST the system for normal operation.
No
GO to S3.
S3 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 Front Control Module), harness side; and between the APIM (Accessory Protocol Interface Module), harness side and ground as follows:
Positive Meter Lead Negative Meter Lead Circuit C2383-23 C240B-9, then ground VME53 (VT/GN) C2383-24 C240B-10, then ground RME53 (BN/WH) C2383-25 C240B-1, then ground VME52 (BU) C2383-26 C240B-2, then ground RME52 (GY/OG)
Is the resistance less than 5 ohms between the APIM (Accessory Protocol Interface Module) and the ACM (Audio Front Control 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 S4.
S4 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) Accessory Protocol Interface Module (APIM). TEST the system for normal operation. If the concern is still present, GO to S5.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
S5 CHECK FOR CORRECT ACM (Audio Front Control Module) OPERATION
- Disconnect all the ACM (Audio Front Control Module) connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the ACM (Audio Front 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 Front Control Module). 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.