GM Service Manual Online
For 1990-2009 cars only

Radio Does Not Connect to Internet Service Provider U45

Step

Action

Yes

No

Schematic Reference: Cellular Telephone Schematics

1

Did you perform Diagnostic System Check - Cellular Communication ?

Go to Step 2

Go to Diagnostic System Check - Cellular Communication

2

  1. Dock the cellular telephone handset.
  2. Turn ON the ignition.
  3. Turn on the radio and set the radio volume.
  4. Attempt to place a call in hands-free mode.
  5. Attempt to place a call using the docked handset.
  6. Attempt to connect the CommuniportPC radio (U45) to the internet service provider.

Does the system operate normally?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Test the modem audio return signal for the following:

    • An open
    • A short to ground
    • A short to voltage

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 4

4

Test the modem audio transmit signal for the following:

    • An open
    • A short to ground
    • A short to voltage

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 5

5

Test the modem audio low reference signal for the following:

    • An open
    • A short to voltage

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 6

6

Inspect for poor connections at the harness connector of the CommuniportPC radio (U45). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 7

7

Inspect for poor connections at the harness connector of the cellular telephone module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 8

8

Replace the cellular telephone module. Refer to Cellular Telephone Module Replacement .

Did you complete the replacement?

Go to Step 10

Go to Step 9

9

Replace the CommuniportPC radio (U45). Refer to Radio Replacement in Entertainment.

Did you complete the replacement?

Go to Step 10

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10

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3