GM Service Manual Online
For 1990-2009 cars only

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 C205 terminal A to ground.
  2. Turn the ignition switch on.

Is the test light on?

--

Go to Step 4

Go to Step 3

3

Repair poor connection or open in circuit 43.

Is the repair complete?

--

Go to Step 15

--

4

  1. Disconnect C205.
  2. Connect a DMM between C205 (female side) terminal A and terminal C.
  3. Press each of the left steering wheel control buttons one at a time.

Are all the resistances approximately equal to the specified values?

    • Volume Up: 1270ohms
    • Volume Down: 1564ohms
    • Source: 1912ohms
    • Mute: 2387ohms
    • Seek Up: 3102ohms
    • Seek Down: 4282ohms
    • Scan: 6652ohms
    • AM/FM 13632ohms

Go to Step 8

Go to Step 5

5

  1. Disconnect the left radio control switch.
  2. Connect a DMM between the left radio control switch pigtail harness connector terminal A and terminal C.
  3. Press each of the left steering wheel control buttons, one at a time.

Are all the resistances approximately equal to the specified values?

    • Volume Up: 1270ohms
    • Volume Down: 1564ohms
    • Source: 1912ohms
    • Mute: 2387ohms
    • Seek Up: 3102ohms
    • Seek Down: 4282ohms
    • Scan: 6652ohms
    • AM/FM 13632ohms

Go to Step 7

Go to Step 6

6

Replace the left radio control switch. Refer to Steering Wheel Control Switches Replacement for service procedure.

Is the repair complete?

--

Go to Step 15

--

7

Replace the inflatable restraint steering wheel module coil. Refer to Inflatable Restraint Steering Wheel Module Coil Replacement in SIR for service procedure.

Is the repair complete?

--

Go to Step 15

--

8

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

Is the test light on?

--

Go to Step 9

Go to Step 10

9

Repair short to B+ on circuit 1796.

Is the repair complete?

--

Go to Step 15

--

10

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 12

Go to Step 11

11

Repair short to ground in circuit 1796.

Is the repair complete?

--

Go to Step 15

--

12

Test for poor connection or open in circuit 1796.

Did you find a poor connection or open in circuit 1796?

--

Go to Step 13

Go to Step 14

13

Repair poor connection or open in circuit 1796.

Is the repair complete?

--

Go to Step 15

--

14

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

Is the repair complete?

--

Go to Step 15

--

15

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 1