GM Service Manual Online
For 1990-2009 cars only

Object Number: 629350  Size: MF
Entertainment Components
Interior Lights Dimming

Circuit Description

These components of the Video Entertainment System (VES) are illuminated when the park lamps are on:

    • The Auxiliary Video Module (AVM) controls.
    • The Rear Seat Audio (RSA) controls.
    • The Second Seat Audio (SSA) controls.
    • The Third Seat Audio (TSA) controls.

When the headlamp and I/P lamp dimmer switch is in the park or head position, circuit 8 provides B+ to the Interface Module (IM), which is bussed and then distributed to the AVM, SSA, TSA, and RSA.

Each component provides a path to ground circuit 150, thus turning their illumination lamps on.

Diagnostic Aids

    • Check for the following conditions:
       - An open in circuit 8 between the IM and the inoperative component.
       - An open in circuit 150 between the IM and the inoperative component.
       - A faulty component (RSA, TSA, SSA, or AVM)
    • An intermittent failure may be very difficult to detect and to diagnose accurately. Faulty electrical connections or wiring causes most intermittent problems. When an intermittent condition is suspected, check the suspected circuits for the following conditions:
       - Poor mating of connector halves or backed out terminals.
       - Improperly formed or damaged terminals.
       - Wire chafing.
       - Poor wire to terminal connections.
       - Dirty or corroded terminals.
       - Damage to connector bodies.
       - Wire broken inside the insulation.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. Checks the integrity of the interior lights dimming circuit within the Video Entertainment System (VES).

  2. Determines whether CKT 8 is open or the component is faulty.

  3. Verifies repairs made to the VES.

Step

Action

Value(s)

Yes

No

1

  1. Turn the headlamp switch to the park lamps position.
  2. Set the dimmer switch at maximum intensity.
  3. Observe the Auxiliary Video Module (AVM) controls, Rear Seat Audio (RSA) controls, Second Seat Audio (SSA) and the Third Seat Audio (TSA) controls.

Does the illumination lamp of at least one of the components mentioned above operate?

--

Go to Step 3

Go to Step 2

2

Refer to Illumination Lamps Inoperative - All Modes table for further diagnosis and repair.

Is the action complete?

--

Go to Step 6

--

3

  1. Leave the park lamps on.
  2. Using a digital multimeter (DMM), measure the voltage by backprobing between ground and the component that is inoperative:
  3. • Auxiliary Video Module (AVM): connector C3 terminal C.
    • Rear Seat Audio (RSA) terminal A6.
    • Second/Third Seat Audio Control (SSA or TSA) terminal A.

Does the voltage measure in the specified range?

More than 8V

Go to Step 4

Go to Step 5

4

  1. Inspect for a poor connection or open in CKT 150 at the inoperative component.
  2. If connection is OK, the replace the component. Refer to one of the following procedures:

Is the repair complete?

--

Go to Step 6

--

5

Repair poor connection or open in CKT 8.

Is the repair complete?

--

Go to Step 6

--

6

  1. Turn the ignition switch off.
  2. Reconnect connectors/components removed.
  3. Verify the operation of the Video Entertainment System (VES).

Does the VES operate normally?

--

System OK

Go to Video System System Check