Hummer H2. Manual — part 217

5

Test the cellular microphone signal circuit
for a short to ground. Refer to Circuit
Testing and Wiring Repairs in Wiring
Systems.
Did you find and correct the condition?

-

Go to Step 13

Go to Step 8

6

Test the drain wire circuit for an open or
short to ground. Refer to Circuit Testing
and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?

-

Go to Step 13

Go to Step 9

7

Test the drain wire for a short to ground.
Did you find and correct the condition?

-

Go to Step 13

Go to Step 10

8

1. Leave the microphone disconnected.

2. Disconnect the vehicle

communication interface module
(VCIM) connector C2.

3. Test the cellular microphone signal

circuit and drain wire circuit for a
short together.

Did you find and correct the condition?

-

Go to Step 13

Go to Step 9

9

Inspect for poor connections at the harness
connector of the cellular microphone. 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 13

Go to Step 12

10

Inspect for poor connections at the harness
connector of the VCIM. 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 13

Go to Step 11

11

Replace the cellular microphone. Refer to
OnStar Microphone Replacement .
Did you complete the replacement?

-

Go to Step 13

-

12 Replace the VCIM. Refer to

Communication Interface Module
Replacement .Did you complete the
replacement?

IMPORTANT:

Perform the OnStar(R) setup procedure.

-

Go to Step 13

-

13

Operate the system in order to verify the
repair.
Did you correct the condition?

-

System OK

Go to Step 2

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Cellular Communication - Hummer H2

VOICE RECOGNITION INOPERATIVE

Voice Recognition Inoperative

ONSTAR STEERING WHEEL CONTROL FUNCTIONS INOPERATIVE

Some vehicles equipped with the OnStar(R) system have the capability of accessing voice mailboxes and other
automated phone systems by means of the steering wheel controls, while the OnStar(R) personal calling (OPC)
feature is in use. If the Talk or Mute button, depending upon the vehicle, on the steering wheel controls are

Step

Action

Yes

No

DEFINITION: The OnStar(R) personal calling feature may not be able to understand some or all words
spoken.

1

Did you perform the Cellular Communication Diagnostic
System Check?

Go to

Step 2

Go to Diagnostic System

Check - Cellular

Communication

2

1. Turn ON the ignition, with the engine OFF.

2. Press the OnStar(R) Call Center button.

3. Ask the OnStar(R) operator if your voice can clearly

be heard.

Does the OnStar(R) operator hear your voice?

IMPORTANT:

The vehicle must be located in a quiet area.

Go to

Step 3

Go to Microphone

Inoperative - Caller

Cannot Be Heard

3

1. Press the call answer button.

2. Pronounce all Hands Free commands. Refer to

OnStar Description and Operation for proper
pronunciation.

Did the OnStar(R) system recognize any of the voice
commands?

Go to

Step 5

Go to Step 4

4

1. Press the call answer button.

2. Have another person pronounce all Hands Free

commands. Refer to OnStar Description and
Operation for proper pronunciation.

Did the OnStar(R) system recognize any of the voice
commands?

Go to

Step 5

Go to OnStar Description

and Operation

5

The system is operational, but cannot identify certain word
commands due to pronunciation. For tips on proper
pronunciation refer to OnStar Description and
Operation .
Operate the system in order to verify the repair.
Did you correct the condition?

System

OK

Go to Step 2

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Cellular Communication - Hummer H2

depressed during an OPC call, the vehicle communication interface module (VCIM) receives the message on
the class 2 serial data bus from either the radio, driver information module, or body control module (BCM).
This message is interpreted as a request to turn any spoken numbers into dual tone multi-frequency (DTMF)
tones to be delivered over the airwaves to the phone system the user is communicating with. Complete
instructions for operation of these features can be found in the information provided to the customer with the
OnStar(R) system.

The steering wheel controls are a resistor network that consist of multiple momentary contact switches and a
series of resistors. The switches and resistor network are arranged so that each switch has a different resistance
value. When a switch is pressed, a voltage drop occurs in the resistor network, which produces a specific
voltage value unique to the switch selected, to be interpreted by either the radio, dash integration module
(DIM), or BCM. In the event the OnStar(R) steering wheel control functions are inoperative, technicians should
refer to Diagnostic System Check - Entertainment System in Entertainment to begin diagnosis of the steering
wheel control concern.

ONSTAR BUTTON LED INOPERATIVE

Test Description

The numbers below refer to the step numbers on the diagnostic table.

3: Determines if the OnStar(R) status LED has the necessary Green LED signal circuit voltage.

5: If the Green LED signal is shorted to voltage then the OnStar(R) three button assembly has been
damaged and the OnStar(R) three button assembly must be replaced.

OnStar Button LED Inoperative

Step

Action

Value

(s)

Yes

No

Schematic Reference:OnStar Schematics
Connector End View Reference:Cellular Communication Connector End Views
DEFINITION: This procedure is for diagnosing problems with the OnStar(R) button assembly LED.

1

Did you perform the Cellular
Communications Diagnostic System
Check?

-

Go to Step 2

Go to Diagnostic

System Check -

Cellular

Communication

2

1. Turn the ignition ON, with engine

OFF.

2. Observe the OnStar(R) status LED.

Did the OnStar(R) status LED turn
GREEN?

-

Go to Testing for

Intermittent

Conditions and Poor

Connections and

Connector Repairs in

Wiring Systems

Go to Step 3

3

Measure the voltage from the Keypad
Green LED Signal circuit to a good
ground.
Does the voltage measure near the

7 V

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Cellular Communication - Hummer H2

NO (OR NOISY) ONSTAR AUDIO

Test Description

The number below refers to the step number on the diagnostic table.

specified value?

Go to Step 6

Go to Step 4

4

Test the Keypad Green LED Signal circuit
for an open, high resistance or a short to
ground. Refer to Circuit Testing and
Wiring Repairs in Wiring Systems.
Did you find and correct the condition?

-

Go to Step 10

Go to Step 5

5

Test the Keypad Green LED Signal circuit
for a short to voltage. Refer to Circuit
Testing and Wiring Repairs in Wiring
Systems.
Did you find and correct the condition?

-

Go to Step 7

Go to Step 8

6

Inspect for poor connections at the harness
connector of the OnStar(R) Button
Assembly. 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 10

Go to Step 7

7

Replace the OnStar(R) Button Assembly.
Refer to OnStar Button Assembly
Replacement .
Did you complete the repair?

-

Go to Step 10

-

8

Inspect for poor connections at the harness
connector of the Vehicle Communication
Interface Module. 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 10

Go to Step 9

9

Replace the Vehicle Communication
Interface Module. Refer to
Communication Interface Module
Replacement .Did you complete the
repair?

IMPORTANT:

Perform the OnStar(R) setup procedure.

-

Go to Step 10

-

10

Operate the system in order to verify the
repair.
Did you correct the condition?

-

System OK

Go to Step 2

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Cellular Communication - Hummer H2