GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2000 🢒 Regal (China) 🢒 Body and Accessories 🢒 Entertainment 🢒 Rear Seat Radio Controls Inoperative

Step

Action

Value(s)

Yes

No

1

Did you review the system operation?

--

Go to Step 2

Go to Symptoms

2
  1. Using a test light, backprobe between connector C240 terminal M to ground.
  2. Turn the ignition switch on.

Does the test light illuminate?

--

Go to Step 3

Go to Step 8

3
  1. Disconnect C240.
  2. Connect a DMM between C240 (female side) terminal M and terminal P.
  3. Press each of the radio control switch buttons one at a time.
  4. Compare the approximate resistance measurements to the values shown.

Are all the resistance measurements approximately equal those shown?
    • VOL Up: 1270ohms
    • VOL Down: 1564ohms
    • SRCE: 1912ohms
    • MUTE: 2387ohms
    • SEEK Up: 3102ohms
    • SEEK Down: 4282ohms
    • SCAN: 6652ohms
    • AM/FM: 13632

Go to Step 5

Go to Step 4

4
  1. Disconnect the radio control switch.
  2. Connect a DMM between the radio control switch harness connector terminal A and terminal D.
  3. Press each of the radio control switch buttons, one at a time.
  4. Compare the approximate resistance measurements to the values shown.

Are all the resistance measurements approximately equal those shown?
    • VOL Up: 1270ohms
    • VOL Down: 1564ohms
    • SRCE: 1912ohms
    • MUTE: 2387ohms
    • SEEK Up: 3102ohms
    • SEEK Down: 4282ohms
    • SCAN: 6652ohms
    • AM/FM: 13632

Go to Step 7

Go to Step 9

5
  1. Using a test light, backprobe between the radio harness connector terminal E6 to ground.
  2. Turn the ignition switch to the on position.

Does the test light illuminate?

--

Go to Step 10

Go to Step 6

6

Using a DMM, measure the resistance between the radio harness connector terminal E6 and ground.

Is the resistance measured same as the specified value?

∞

Go to Step 7

Go to Step 11

7

Inspect circuit  1796.

Is there a poor connection or open in circuit 1796?

--

Go to Step 12

Go to Step 13

8

Repair poor connection or open in circuit 43.

Is the repair complete?

--

Go to Step 14

--

9

Replace the radio control switch. Refer to Rear Seat Audio Control Replacement .

Is the repair complete?

--

Go to Step 14

--

10

Repair the short to B+ on circuit 1796.

Is the repair complete?

--

Go to Step 14

--

11

Repair the short to ground in circuit 1796.

Is the repair complete?

--

Go to Step 14

--

12

Repair the poor connection or open in circuit 1796.

Is the repair complete?

--

Go to Step 14

--

13

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

Is the repair complete?

--

Go to Step 14

--

14

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 1