GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Using a test light, backprobe between the radio harness connector C1 terminal 10 to ground.

Does the test light illuminate?

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Go to Step 3

Go to Step 2

2

Repair a poor connection or open in circuit 640.

Is the repair complete?

--

Go to Diagnostic System Check - Radio/Audio System

--

3

Replace the radio. Refer to Radio Replacement for service procedure.

Is the repair complete?

--

Go to Diagnostic System Check - Radio/Audio System

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