GM Service Manual Online
For 1990-2009 cars only

Test Description

This procedure determines the problem with the OnStarĀ® Center commands if they are inoperative. The vehicle must be in an area capable of transmitting and receiving cellular signals. The following numbers refer to the steps in the table.

  1. This step verifies that the phone is presently capable of placing a call. This step also insures that the OnStarĀ® system is properly configured.

  2. This step tests the Horn Honk command from the OnStarĀ® Call Center.

  3. This step tests the Lock command from the OnStarĀ® Call Center.

  4. This step tests the Unlock command from the OnStarĀ® Call Center.

  5. This step tests the Lights Flash command from the OnStarĀ® Call Center.

Step

Action

Value(s)

Yes

No

1

Did you perform the OnStarĀ® Diagnostic System Check?

--

Go to Step 2

Go to OnStar System Check

2

  1. Turn ON the ignition, with the engine OFF.
  2. Activate the OnStarĀ® Call Center button.
  3. Ask the OnStarĀ® Call Center operator to configure the vehicle.
  4. Activate the Call End button.

Is the repair complete?

--

Go to Step 3

 

3

  1. Turn ON the ignition, with the engine OFF.
  2. Activate the OnStarĀ® Call Center button.
  3. With a scan tool observe the OnStarĀ® Horn parameter.
  4. Ask the OnStarĀ® Call Center operator to command ON and OFF the Horn.
  5. Activate the Call End button.

Does the horn command ON and OFF?

--

Go to Step 5

Go to Step 4

4

With a scan tool command the horn relay ON and OFF.

Does the horn turn ON and OFF with each command?

--

Go to Step 11

Go to Diagnostic System Check - Horns in Horns

5

  1. Turn ON the ignition, with the engine OFF.
  2. Activate the OnStarĀ® Call Center button.
  3. With a scan tool observe the OnStarĀ® lock parameter.
  4. Ask the OnStarĀ® Call Center operator to command ON and OFF the locks.
  5. Activate the Call End button.

Does the lock command ON and OFF?

--

Go to Step 7

Go to Step 6

6

With a scan tool command the lock relay ON and OFF.

Does the lock turn ON and OFF with each command?

--

Go to Step 11

Go to Diagnostic System Check - Power Door Systems in Doors

7

  1. Turn ON the ignition, with the engine OFF.
  2. Activate the OnStarĀ® Call Center button.
  3. With a scan tool observe the OnStarĀ® unlock parameter.
  4. Ask the OnStarĀ® Call Center operator to command ON and OFF the locks.
  5. Activate the Call End button.

Does the Unlock command ON and OFF?

--

Go to Step 9

Go to Step 8

8

With a scan tool command the unlock relay ON and OFF.

Does the unlock turn ON and OFF with each command?

--

Go to Step 11

Go to Diagnostic System Check - Power Door Systems in Doors

9

  1. Turn ON the ignition, with the engine OFF.
  2. Activate the OnStarĀ® Call Center button.
  3. With a scan tool observe the OnStarĀ® lights parameter.
  4. Ask the OnStarĀ® Call Center operator to command ON and OFF the lights.
  5. Activate the Call End button.

Does the lights command ON and OFF?

--

Go to Step 12

Go to Step 10

10

With a scan tool command the headlamp relay ON and OFF.

Do the headlamps turn ON and OFF with each command?

--

Go to Step 11

Go to Diagnostic System Check - Lighting Systems in Lighting Systems

11

Replace the vehicle interface unit (VIU). Refer to OnStar Vehicle Interface Unit Replacement .

Is the repair complete?

--

Go to Step 12

--

12

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3