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 terminal F1 to ground.

Is the test light on?

--

Go to Step 3

Go to Step 2

2

Repair poor connection or open in circuit 640.

Is the repair complete?

--

Go to Diagnostic System Check - Radio/Audio System

--

3

Service 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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