Hummer H2. Manual — part 214

z

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

Action Taken When the DTC Sets

z

The OnStar(R) status LED turns RED.

z

The OnStar(R) Call Center cannot locate the vehicle.

Conditions for Clearing the DTC

z

The VCIM detects the presence of the cellular and navigation antenna.

z

A history DTC clears after 50 malfunction free ignition cycles.

z

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

DTC B2483 or B2484

Step

Action

Values Yes

No

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

1

Did you perform the Cellular Communication Diagnostic
System Check?

-

Go to

Step

2

Go to Diagnostic

System Check -

Cellular

Communication

2

1. Disconnect the blue navigation antenna coax

connector from the cellular and navigation antenna.

2. Disconnect the navigation antenna coax from the

vehicle communication interface modules (VCIM).

3. Measure the resistance from the center conductor of

the coax to the metal outer shield.

Does the meter read out of limits?

NOTE:

Using a DMM to measure the resistance of the
navigation antenna coax from the center conductor to
the outer shield while the antenna is still connected
will damage the navigation antenna.

-

Go to

Step

3

Go to Step 4

3

Measure the resistance of the navigation antenna coax
center conductor from end to end.
Does the resistance measure greater than the specified
value?

1.0

ohm

Go to

Step

4

Go to Step 5

4

Replace the navigation antenna coax.
Did you complete the replacement?

-

Go to

Step

7

-

Inspect for poor connections at the cellular and navigation
antenna and the harness connector of the VCIM. Refer to

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Cellular Communication - Hummer H2

DTC U1500

Circuit Description

This DTC indicates an internal fault and is set within the vehicle communication interface module (VCIM). No
external circuits are involved.

Conditions for Running the DTC

The microprocessor runs the program to detect an internal fault during module power up and every 10 seconds
thereafter until the module re-enters the sleep mode.

Conditions for Setting the DTC

The VCIM detects an internal communication malfunction.

Action Taken When DTC Sets

z

The OnStar(R) status LED turns RED.

5

Testing for Intermittent Conditions and Poor
Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?

-

Go to

Step

7

Go to Step 6

6

Replace the cellular and navigation antenna. Refer to
Antenna Assembly Replacement - Cellular and
Navigation .
Is the repair complete?

-

Go to

Step

7

-

7

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

8

System OK

8

Replace the VCIM. Refer to Communication Interface
Module Replacement .

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?

IMPORTANT:

Perform the OnStar(R) setup procedure.

-

Go to

Step

2

-

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Cellular Communication - Hummer H2

z

The vehicle is unable to connect to the OnStar(R) Call Center.

Conditions for Clearing the DTC

z

A current DTC clears when the malfunction is no longer present.

z

A history DTC clears after 50 malfunction free ignition cycles.

Diagnostic Aids

z

The diagnostic procedure used for DTC U1500 in OnStar(R) systems with single module generations of
OnStar(R) differ greatly from previous generations with 2 modules. While these older generations
denoted a failure of the 3-wire bus between the modules by setting a U1500, single module OnStar(R)
systems use this DTC to denote an internal module failure. The determination of whether a one or 2-
module generation of OnStar(R) is used should be confirmed. Refer to OnStar Description and
Operation .

z

This DTC may be stored as a history DTC without affecting the operation of the module. If stored only as
a history DTC and not retrieved as a current DTC, do not replace the VCIM.

z

If this DTC is retrieved as both a current and history DTC, replace the VCIM.

DTC U1500

ONSTAR SYMPTOM DIAGNOSIS

Step

Action

Yes

No

1

Did you perform the Cellular Communication
Diagnostic System Check?

Go to

Step 2

Go to Diagnostic System Check

- Cellular Communication

2

1. Install a scan tool.

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

3. Retrieve DTCs from the vehicle communication

interface module (VCIM).

Is the DTC retrieved as a current DTC?

Go to

Step 3

Go to Diagnostic Aids

3

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

IMPORTANT:

Perform the OnStar(R) setup procedure.

Go to

Step 4

-

4

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 2

System OK

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Cellular Communication - Hummer H2

System Description

This symptom table will enable the user to verify the customer complaint and narrow it to its source. If there is a
concern with voice recognition or OnStar(R) steering wheel control function, technicians should proceed
directly to the applicable diagnostic in Symptoms - Cellular Communication .

Diagnostic Aids

z

The customer concern may have been due to a lack of cellular service in a given area or a failure in the
National Cellular Network infrastructure that has since been corrected.

z

If the prompt OnStar request ended is heard without pressing the white dot button at the end of an OnStar
(R) keypress, the OnStar(R) system at one time has made a successful cellular connection, but was unable
to complete the call. If repeated calls are placed with this result, contact the General Motors Technical
Assistance Center.

z

Inaccurate or aged global positioning system (GPS) position may have been due to the temporary loss of
GPS signal reception by the vehicle in instances such as driving through tunnels or parking structures
which restrict the navigation antenna from a clear view of the satellites in the sky.

OnStar Symptom Diagnosis

IMPORTANT: To successfully diagnose and repair the OnStar(R) system it is necessary to

comprehend its operation. Technicians should read and understand the OnStar
Description and Operation before attempting to repair an OnStar(R) system.

Step

Action

Yes

No

1

Did you perform the 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. Observe the OnStar(R) status

LED.

Does the LED turn GREEN?

Go to Step 3

Go to OnStar Button LED

Inoperative

3

1. Turn the radio ON.

2. Set volume to a comfortable

level.

3. Press the OnStar(R) Call Center

button.

4. Wait approximately 10 seconds

then end the call by pressing the
white dot button.

Does both the OnStar(R) LED blink
after the OnStar(R) keypress is made
and the call ended after pressing the

Go to OnStar One or More

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Cellular Communication - Hummer H2