GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform Radio/Audio System Check?

--

Go to Step 2

Go to Radio/Audio System Check

2

  1. Ensure that the vehicle is OFF.
  2. Test CKT 835 (DK GRN) for voltage.

Is voltage present in CKT 835 (DK GRN)?

B+

Go to Step 8

Go to Step 3

3

Disconnect the vehicle interface unit (VIU).

Is voltage present in CKT 835 (DK GRN)?

--

Go to Step 10

Go to Step 4

4

  1. Disconnect the radio connector C3.
  2. Test CKT 835 (DK GRN) for a short to ground.

Is a short to ground present in CKT 835 (DK GRN)?

--

Go to Step 5

Go to Step 6

5

Repair the short to ground in CKT 835 (DK GRN).

Is the repair complete?

--

Go to Radio/Audio System Check

--

6

Test CKT 835 (DK GRN) for an open circuit.

Is an open present in CKT 835 (DK GRN)?

--

Go to Step 7

Go to Step 9

7

Repair the open in CKT 835 (DK GRN).

Is the repair complete

--

Go to Radio/Audio System Check

--

8

Important: Data transmission can be identified as a momentary change in frequency. Monitor the J 39200 DMM while operating the phone.

  1. Test CKT 835 (DK GRN) for data transmission.
  2. Operate the phone.

Is data transmission observed?

100-1000 HZ

Go to Step 9

Go to Step 10

9

Service the radio. Refer to Radio Replacement .

Is service of the radio complete?

--

Go to Radio/Audio System Check

--

10

Service the vehicle interface unit (VIU).

Is service of the VIU complete?

--

Go to Radio/Audio System Check

--