GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2000 🢒 Sonoma Pickup - 4WD 🢒 Body and Accessories 🢒 Entertainment 🢒 Rear Seat Radio Controls Inoperative

Step

Action

Value(s)

Yes

No

1

Did you review the radio/audio system operation and perform the necessary inspections?

--

Go to Step 2

Go to Symptoms

2

Verify that the rear seat radio controls are inoperative.

Do the rear seat radio controls operate normally?

--

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

Go to Step 3

3

Is the power ON indicator inoperative only?

--

Go to Step 4

Go to Step 6

4

Test CKT 314 (PNK) at the rear seat audio control for voltage.

Is voltage present in CKT 314 (PNK)?

--

Go to Step 19

Go to Step 5

5

Repair the open in CKT 314 (PNK). Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 35

--

6

When the PWR button is pressed to select ON, verify the that the following conditions exist:

    • Power indicator ON inoperative.
    • Rear door speakers do not mute.
    • Rear door speaker audio is at a loud unadjustable volume.

Do the conditions exist?

--

Go to Step 7

Go to Step 12

7

Test CKT 314 (PNK) for a short to ground.

Is a short to ground present in CKT 314 (PNK)?

--

Go to Step 8

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

8

Disconnect the rear seat audio control.

Is a short to ground present in CKT 314 (PNK)?

--

Go to Step 9

Go to Step 19

9

Disconnect the radio.

Is a short to ground present in CKT 314 (PNK)?

--

Go to Step 10

Go to Step 23

10

Disconnect the amplifier.

Is a short to ground present in CKT 314 (PNK)?

--

Go to Step 11

Go to Step 28

11

Repair the short to ground in CKT 314 (PNK). Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 35

--

12

Are both channels inoperative?

--

Go to Step 14

Go to Step 13

13

Is the left channel inoperative?

--

Go to Step 26

Go to Step 27

14
  1. Turn the ignition switch to ACC position.
  2. Connect (backprobe) a DMM to cavity M for CKT 1011 (LT GRN) of the rear seat audio control.
  3. Press and hold the PWR button.

Is voltage within the specified range?

3.1-3.3 V

Go to Step 20

Go to Step 15

15

Test CKT 1301 (DK GRN) for an open circuit.

Is an open present in CKT 1301 (DK GRN)?

--

Go to Step 16

Go to Step 17

16

Repair the open in CKT 1301 (DK GRN). Refer to Circuit Testing and Wiring Repairs in Wiring Systens.

Is the repair complete?

--

Go to Step 35

--

17

Test CKT 1050 (BLK ) for an open circuit.

Is an open present in CKT 1050 (BLK)?

--

Go to Step 18

Go to Step 19

18

Repair the open in CKT 1050 (BLK). Refer to Circuit Testing and Wiring Repairs in Wiring Systens.

Is the repair complete?

--

Go to Step 35

--

19

Replace the rear seat audio control. Refer to Rear Seat Audio Control Replacement .

Is the replacement complete?

--

Go to Step 35

--

20
  1. Turn the ignition switch to the OFF position.
  2. Test CKT 1011 (LT GRN) for an open circuit.

Is an open present in CKT 1011 (LT GRN)?

--

Go to Step 21

Go to Step 22

21

Repair the open in CKT 1011 (LT GRN). Refer to Circuit Testing and Wiring Repairs in Wiring Systens.

Is the repair complete?

--

Go to Step 35

--

22
  1. Turn the ignition switch to the ACC position.
  2. Press and release the PWR button of the rear seat audio module.
  3. Test CKT 314 (PNK) at the radio (backprobe) for voltage.

Is voltage within the specified range?

9-16 V

Go to Step 24

Go to Step 23

23

Service the radio. Refer to Radio Replacement .

Is service of the radio complete?

--

Go to Step 35

--

24

Test CKT 314 (PNK) at the amplifier (backprobe) for voltage.

Is voltage within the specified range?

9-16 V

Go to Step 26

Go to Step 25

25

Repair the open in CKT 314 (PNK). Refer to Circuit Testing and Wiring Repairs in Wiring Systens.

Is the repair complete?

--

Go to Step 35

--

26

Important: The audio output signal can be identified as a fluctuating AC voltage. Measure from the channel output cavity to the channel common ground cavity.

  1. Verify that the system is ON.
  2. Test for left channel audio output at the amplifier.

Is the left channel audio output present?

100-400 mV AC

Go to Step 29

Go to Step 28

27

Important: The audio output signal can be identified as a fluctuating AC voltage. Measure from the channel output cavity to the channel common ground cavity.

  1. Verify that the system is ON.
  2. Test for right channel audio output at the amplifier.

Is the right channel audio output present?

100-400 mV AC

Go to Step 29

Go to Step 28

28
  1. Service the amplifier. Refer to Radio Speaker Amplifier Replacement .
  2. Before reinstalling the amplifier, inspect the harness for bare wire(s). Repair the harness as necessary.

Is service of the amplifier complete?

--

Go to Step 35

--

29

Important: The audio output signal can be identified as a fluctuating AC voltage.

Measure from the channel input cavity to the channel common ground cavity.

Test for audio input to the rear seat audio module.

Is the audio signal present?

100-400 mV AC

Go to Step 19

Go to Step 30

30

Are both channels inoperative?

--

Go to Step 31

Go to Step 32

31

Repair the open in CKT 372 (BLK/WHT). Refer to Circuit Testing and Wiring Repairs in Wiring Systens.

Is the repair complete

--

Go to Step 35

--

32

Is the right channel input inoperative?

--

Go to Step 33

Go to Step 34

33

Repair the open in CKT 368 (DK GRN/WHT). Refer to Circuit Testing and Wiring Repairs in Wiring Systens.

Is the repair complete?

--

Go to Step 35

--

34

Repair the open in CKT 367 (BRN/WHT). Refer to Circuit Testing and Wiring Repairs in Wiring Systens.

Is the repair complete?

--

Go to Step 35

--

35

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3