Pinpoint Test I: The Audio Input Jack Is Inoperative Or Has Poor Sound Quality

Information and Entertainment System

Pinpoint Test I: The Audio Input Jack Is Inoperative Or Has Poor Sound Quality

Normal Operation

The audio input jack is present on vehicles without SYNC(R). Audio signals are sent from the audio input jack to the Audio Front Control Module (ACM). There are no external power or ground circuits to the audio input jack.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- Audio input jack

- ACM (Audio Front Control Module)

PINPOINT TEST I : THE AUDIO INPUT JACK IS INOPERATIVE OR HAS POOR SOUND QUALITY

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

NOTE: Before carrying out this pinpoint test, make sure the MP3 device is operating correctly.

I1 CHECK THE AUDIO INPUT

- Connect: Multi-Media Interface Tester.

- Using the Multi-Media Interface Tester, attempt to play a file using the audio input jack.

Does the file play correctly?

Yes
The system is operating correctly at this time. The concern may be with the customer device.

No
GO to I2.

I2 CHECK THE AUDIO INPUT JACK CIRCUITS FOR A SHORT TO VOLTAGE

- Ignition OFF.

- Disconnect: Audio Input Jack C3312.

- Disconnect: ACM (Audio Front Control Module) C240B.

- Ignition ON.

- Measure the voltage between the audio input jack, harness side and ground as follows:

Positive Meter Lead Negative Meter Lead Circuit C3312-1 Ground VME46 (BU/GN) C3312-2 Ground RME46 (WH/GN) C3312-3 Ground RME45 (YE/GN) C3312-4 Ground VME45 (BU)





Is any voltage present?

Yes
REPAIR the circuit in question. TEST the system for normal operation.

No
GO to I3.

I3 CHECK THE AUDIO INPUT JACK OR MEDIA HUB CIRCUITS FOR AN OPEN OR SHORT TO GROUND

- Ignition OFF.

- Measure the resistance between the audio input jack, harness side and the ACM (Audio Front Control Module), harness side; and between the audio input jack, harness side and ground as follows:

Positive Meter Lead Negative Meter Lead Circuit C3312-1 C240A-18, then ground VME46 (BU/GN) C3312-2 C240A-6, then ground RME46 (WH/GN) C3312-3 C240A-5, then ground RME45 (YE/GN) C3312-4 C240A-17, then ground VME45 (BU)





Is the resistance less than 5 ohms between the audio input jack and the ACM (Audio Front Control Module), and greater than 10,000 ohms between the audio input jack and ground?

Yes
GO to I4.

No
REPAIR the circuit in question. TEST the system for normal operation.

I4 ISOLATE THE AUDIO INPUT JACK

- Connect: ACM (Audio Front Control Module) C240A.

- Install a new audio input jack. Refer to Audio Input Jack Audio Input Jack.

- Connect: Multi-Media Interface Tester.

- Using the Multi-Media Interface Tester, attempt to play a file using the audio input jack.

Does the system operate correctly?

Yes
The concern was caused by an inoperative audio input jack. The system is operating correctly at this time.

No
GO to I5.

I5 CHECK FOR CORRECT ACM (Audio Front Control Module) OPERATION

- Ignition OFF.

- 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 determine if 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.