GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

Schematic Reference: Radio/Audio System Schematics

1

Did you review the Radio/Audio System Description and Operation and perform the necessary inspections?

--

Go to Step 2

Go to Radio/Audio System Description and Operation

2

  1. Turn ON the ignition, with the engine OFF.
  2. Turn ON the radio.
  3. Adjust the radio balance and fade controls to each speaker.

Do all of the speakers operate properly?

--

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

Go to Step 3

3

Are all of the speakers inoperative?

--

Go to Step 10

Go to Step 4

4

Is an audio amplifier installed in the Radio/Audio System?

--

Go to Step 6

Go to Step 5

5

  1. Turn OFF the ignition.
  2. Disconnect the radio.
  3. Momentarily touch a 1.5 volt battery between the appropriate speaker output circuits of the radio.

Does the speaker emit an audible pop?

--

Go to Step 19

Go to Step 9

6

  1. Turn OFF the ignition.
  2. Disconnect the audio amplifier.
  3. Turn ON the ignition, with the engine OFF.
  4. Turn ON the radio.
  5. Adjust the radio volume to 50 percent.
  6. Test the appropriate speaker input circuits of the audio amplifier for AC voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Does the voltage measure greater than the specified value?

0.020 V

Go to Step 7

Go to Step 8

7

Test the appropriate speaker output circuits of the audio amplifier for a short, high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 25

Go to Step 18

8

Test the appropriate speaker input circuits of the audio amplifier for a short, high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 25

Go to Step 19

9

Test the appropriate speaker output circuits of the radio for a short or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 25

Go to Step 21

10

  1. Turn OFF the ignition.
  2. Disconnect the radio.
  3. Test the entertainment and comfort serial data circuit(s) of the radio for a short or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 25

Go to Step 11

11

Test the radio on signal circuit(s) of the radio for a short or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 25

Go to Step 12

12

Is a BOSE audio amplifier installed in the Radio/Audio System?

--

Go to Step 15

Go to Step 13

13

Test the speaker output circuits of the radio for a short. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 25

Go to Step 14

14

Is an audio amplifier installed in the Radio/Audio System?

--

Go to Step 15

Go to Step 19

15

  1. Disconnect the audio amplifier.
  2. Test the battery positive voltage circuit of the audio amplifier for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 25

Go to Step 16

16

Test the audio amplifier control circuit of the audio amplifier for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 25

Go to Step 17

17

Test the ground circuit of the audio amplifier for high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 25

Go to Step 20

18

  1. Disconnect the speaker.
  2. Adjust the radio volume to 50 percent.
  3. Test the appropriate speaker input circuits of the speaker for AC voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Does the voltage measure greater than the specified value?

0.020  V

Go to Step 21

Go to Step 20

19

Inspect for poor connections at the harness connector of the radio. 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 25

Go to Step 22

20

Inspect for poor connections at the harness connector of the audio amplifier. 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 25

Go to Step 23

21

Inspect for poor connections at the harness connector of the appropriate speaker. 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 25

Go to Step 24

22

Replace the Radio. Refer to Radio Replacement .

Did you complete the replacement?

--

Go to Step 25

--

23

Replace the audio amplifier. Refer to Radio Speaker Amplifier Replacement .

Did you complete the replacement?

--

Go to Step 25

--

24

Replace the suspect speaker. Refer to Speaker Replacement .

Did you complete the replacement?

--

Go to Step 25

--

25

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2