Overview - Sound System, Basic Sound System, 8RM

The basic sound system (8RM) consists of the following components:

• One speaker on the left and right side of the instrument panel
• One speaker in the left and right front doors
• Two speakers in the left and right rear doors

Fig 1: 8 Speaker Circuit Diagram (8RM)

Courtesy of AUDI OF AMERICA, LLC

1. Information Electronics Control Module 1 -J794- Behind the Glove Compartment
2. Left Front Treble Speaker -R20- /Right Front Treble Speaker -R22- on Left/Right Sides of Instrument Panel
3. Left Front Bass Speaker -R21- /Right Front Bass Speaker -R23- in Front Doors
4. Left Rear Treble Speaker -R14- /Right Rear Treble Speaker -R16- in Rear Doors
5. Left Rear Bass Speaker -R15- /Right Rear Bass Speaker -R17- in Rear Doors
6. MOST Bus

Fault Finding is performed using the "Guided Fault Finding"  on the Vehicle Diagnostic Tester.

Notes on MOST Bus

The optical data bus "MOST Bus" is used in addition to the CAN Bus.

A fiber-optic cable is used. Fiber optic cables are routed inside corrugated tubes for protection.

Replace the complete fiber-optic cable if possible.

The front surfaces of the connectors must not get dirty.

If disconnecting the connectors: Attach the Fiber-Optic Repair Set - Connector Protective Caps: VAS6223/9  .

Fig 2: Fiber-Optic Conductor Repair Set VAS 6223A

Courtesy of AUDI OF AMERICA, LLC

When routing fiber-optic cables, make sure not to go below the minimum bending radius of 25 mm. Do not crush or kink the fiber-optic cables.

Repairing fiber optic cables. Refer to FIBER-OPTIC CABLES, REPAIRING .