GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Cellular Telephone System Check?

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Go to Step 2

Go to Cellular Telephone System Check

2

  1. Turn on the radio.
  2. Test the operation of the cellular telephone.

Is the audio noisy when the radio is on also?

--

Go to Radio/Audio System Check in Entertainment

Go to Step 3

3

Using a J 39200 digital multimeter (DMM) set to the ohms scale, test the coaxial cable in both the center conductor and the shield for continuity between the following components:

    • The cellular telephone module
    • The cellular telephone handset

Is the circuit continuity OK?

--

Go to Step 5

Go to Step 4

4

Replace the coaxial cable.

Is the repair complete?

--

Go to Cellular Telephone System Check

--

5

Using a DMM, test for continuity between the following terminals:

    • The radio connector terminal E9 and cellular telephone handset jumper connector C
    • The radio connector terminal E10 and cellular telephone handset jumper connector  G
    • The radio connector terminal E11 and cellular telephone handset jumper connector A

Is the circuit continuity OK?

--

Go to Step 7

Go to Step 6

6

Repair the open in the following circuits:

    • CKT 372 (BLK/WHT)
    • CKT 367 (BRN/WHT)
    • CKT 368 (DK GRN/WHT)

Is the repair complete?

--

Go to Cellular Telephone System Check

--

7

Test the cellular telephone handset-to-harness connector jumper wiring for continuity.

Is the wiring OK?

--

Go to Step 9

Go to Step 8

8

Replace the cellular telephone handset-to-harness connector jumper.

Is the repair complete?

--

Go to Cellular Telephone System Check

--

9

Test the cellular telephone operation using a known good cellular telephone handset.

Is the sound restored?

--

Go to Step 10

Go to Step 11

10

Replace the cellular telephone handset. Refer to Cellular Telephone Replacement .

Is the repair complete?

--

Go to Cellular Telephone System Check

--

11

  1. Inspect the cellular telephone module connector for poor terminal contact.
  2. If the contact is OK, replace the cellular telephone module. Refer to Radio Frequency Booster and Bracket Assembly Replacement .

Is the repair complete?

--

Go to Cellular Telephone System Check

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