Hummer H2. Manual - part 213

The OnStar(R) status LED turns RED.

Conditions for Clearing the DTC

The VCIM powers the button assembly through the keypad supply voltage circuit for 11.5 ms, turns the
power off, then waits for 50 ms and sees a voltage value less than 1.8 volts on this circuit.

A history DTC clears after 50 malfunction free ignition cycles.

The VCIM receives the clear DTC command from the scan tool.

Test Description

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

2: This step checks that the Vehicle Communication Interface Module is sending out the proper supply
voltage.

DTC B2476

Step

Action

Values Yes

Schematic Reference:OnStar Schematics
Connector End View Reference:Cellular Communication Connector End Views

Did you perform the Cellular Communications
Diagnostic System Check?

Go to

Step

Go to Diagnostic

System Check -

Cellular

Communication

1. Turn the ignition OFF.

2. Disconnect the OnStar(R) button assembly

connector.

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

4. Measure the voltage from the Keypad Supply

Voltage circuit to a good ground.

Does the voltage measure greater than the specified
value?

9 V

Go to

Step

Go to Step 3

Test the Keypad Supply Voltage 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

Go to Step 8

Test the Keypad Supply Voltage 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

Go to Step 5

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

Go to

Step

Go to Step 6

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Cellular Communication - Hummer H2

DTC B2482

Circuit Description

The OnStar(R) button assembly consists of three buttons, Call/Answer, OnStar(R) Call Center and OnStar(R)
Emergency. Ten volts is supplied to the button assembly on the Keypad Supply Voltage circuit. Each of the
buttons, when pressed, completes the circuit across a resister allowing a specific voltage to be returned to the
Vehicle Communication Interface Module on the keypad signal circuit. Depending upon the voltage range
returned, the Vehicle Communication Interface Module is able to identify which button has been pressed.

Conditions for Running the DTC

The ignition must be in the RUN or ACC position.

The system voltage is at least 9.5 volts and no more than 15.5 volts.

All the above conditions are present for greater than 15 seconds.

Test the Keypad 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

Go to Step 7

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

Go to Step 9

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

Go to Step 10

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

Go to

Step

Replace the VCIM. Refer to Communication Interface
Module Replacement .Did you complete the
replacement?

IMPORTANT:

Perform the OnStar(R) setup procedure.

Go to

Step

1. Use the scan tool in order to clear the DTCs.

2. Operate the vehicle within the Conditions for

Running the DTC as specified in the supporting
text.

Does the DTC reset?

Go to

Step

System OK

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Cellular Communication - Hummer H2

Conditions for Setting the DTC

A button is depressed or stuck for more than 15 seconds.

The above conditions are present for greater than 15 seconds.

Action Taken When the DTC Sets

The Vehicle Communication Interface Module will ignore all inputs from the OnStar(R) button assembly.

No calls can be placed.

The OnStar(R) status LED turns RED.

Conditions for Clearing the DTC

The button will be declared unstuck after a 50 ms normal cycle.

A history DTC clears after 50 malfunction free ignition cycles.

The Vehicle Communication Interface Module receives the clear DTC command from the scan tool.

Test Description

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

2: This step tests the at rest state of the Keypad Signal circuit.

DTC B2482

Step

Action

Value

(s)

Yes

Schematic Reference:OnStar Schematics
Connector End View Reference:Cellular Communication Connector End Views

Did you perform the Cellular Communications Diagnostic
System Check?

Go to

Step

Go to Diagnostic

System Check -

Cellular

Communication

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

2. Measure the voltage from the Keypad Signal circuit

at the Vehicle Communication Interface Module
connector to a good ground.

Does the voltage measure greater than the specified value?

0 V

Go to

Step

Go to Step 4

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

Go to

Step

Go to Step 5

Test the Keypad Supply Voltage circuit for an open or
short. Refer to Circuit Testing and Wiring Repairs in

Go to

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Cellular Communication - Hummer H2

DTC B2483 OR B2484

Circuit Description

The navigation portion of the cellular and navigation antenna is connected to the vehicle communication
interface module (VCIM) with a RG-174 coax cable. The VCIM polls the data from the antenna once every
second.

Conditions for Running the DTC

The ignition must be in the RUN or ACC position.

The system voltage is at least 9.5 volts and no more than 15.5 volts.

All the above conditions are present for greater than 1 second.

Conditions for Setting the DTC

The VCIM does not detect a navigation signal.

Wiring Systems.
Did you find and correct the condition?

Step

Go to Step 6

Go to

Step

Go to Step 7

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

Go to Step 8

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

Go to

Step

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

IMPORTANT:

Perform the OnStar setup procedure.

Go to

Step

1. Use the scan tool in order to clear the DTCs.

2. Operate the vehicle within the Conditions for

Running the DTC as specified in the supporting
text.

Does the DTC reset?

Go to

Step

System OK

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Cellular Communication - Hummer H2

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