Hummer H2. Manual — part 1343

1. Separate the connector halves.

2. Visually inspect the connector halves for contamination. Contamination may result in a white or green

build-up within the connector body or between terminals. This causes high terminal resistance,
intermittent contact, or an open circuit. An underhood or underbody connector that shows signs of
contamination should be replaced in its entirety: terminals, seals, and connector body.

3. Using an equivalent male terminal from the J-38125 , test that the retention force is significantly different

between a good terminal and a suspect terminal. Replace the female terminal in question. See Special
Tools and Equipment .

Flat Wire (Dock and Lock) Connectors

or

There are no serviceable parts for flat wire (dock and lock) connectors on the harness side or the component
side.

Follow the procedure below in order to test terminal contact.

1. Remove the component in question.

2. Visually inspect each side of the connector for signs of contamination. Avoid touching either side of the

connector as oil from your skin may be a source of contamination as well.

3. Visually inspect the terminal bearing surfaces of the flat wire circuits for splits, cracks, or other

imperfections that could cause poor terminal contact. Visually inspect the component side connector to
ensure that all of the terminals are uniform and free of damage or deformation.

4. Insert the appropriate adapter from the J 42675 on the flat wire harness connector in order to test the

circuit in question. See Special Tools and Equipment .

INDUCING INTERMITTENT FAULT CONDITIONS

In order to duplicate the customer's concern, it may be necessary to manipulate the wiring harness if the
malfunction appears to be vibration related. Manipulation of a circuit can consist of a wide variety of actions,
including:

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Wiggling the harness

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Disconnecting a connector and reconnecting

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Stressing the mechanical connection of a connector

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Pulling on the harness or wire in order to identify a separation/break inside the insulation

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Relocating a harness or wires

All these actions should be performed with some goal in mind. For instance, with a scan tool connected,
wiggling the wires may uncover a faulty input to the control module. The snapshot option would be appropriate
here. Refer to Scan Tool Snapshot Procedure . You may need to load the vehicle in order to duplicate the
concern. This may require the use of weights, floorjacks, jackstands, frame machines, etc. In these cases you are
attempting to duplicate the concern by manipulating the suspension or frame. This method is useful in finding

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Wiring Systems - Hummer H2

harnesses that are too short and their connectors pull apart enough to cause a poor connection. A DMM set to
Peak Min/Max mode and connected to the suspect circuit while testing can yield desirable results. Refer to
Testing for Electrical Intermittents .

Certainly, using the senses of sight, smell, and hearing while manipulating the circuit can provide good results
as well.

There may be instances where circuit manipulation alone will not meet the required criteria for the fault
condition to appear. In such cases it may be necessary to expose the suspect circuit to other conditions while
manipulating the harness. Such conditions would include high moisture conditions, along with exceptionally
high or low temperatures. The following discusses how to expose the circuit to these kinds of conditions.

Salt Water Spray

Some compounds possess the ability to conduct electricity when dissolved in water such as ordinary salt. By
mixing table salt with water in sufficient quantities, you can enhance the conductive properties of water so that
any circuit which may be sensitive to moisture will more readily fail when liberally sprayed with this mixture.

Mixing 0.35L (12 oz) of water with approximately 1 tablespoon of salt will yield a salt solution of 5 percent.
Fill a normal spray bottle with this mixture. This mixture is sufficient to enhance the water's own conductivity.
This may cause the circuit to fail more easily when sprayed. Once the mixture is completed, spray the suspect
area liberally with the solution. Then, while monitoring either a scan tool or DMM, manipulate the harness as
discussed previously.

High Temperature Conditions

Tools Required

J 25070 Heat Gun. See Special Tools and Equipment .

High Temperature Conditions

If the complaint tends to be heat related, you can simulate the condition using the J 25070 . See Special Tools
and Equipment .

Using the heat gun, you can heat up the suspected area or component. Manipulate the harnesses under high
temperature conditions while monitoring the scan tool or DMM to locate the fault condition.

The high temperature condition may be achieved simply by test driving the vehicle at normal operating
temperature. If a heat gun is unavailable, consider this option to enhance your diagnosis. This option does not
allow for the same control, however.

Low Temperature Conditions

Depending on the nature of the fault condition, placing a fan in front of the vehicle while the vehicle is in the
shade can have the desired effect.

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Wiring Systems - Hummer H2

If this is unsuccessful, use local cooling treatments such as ice or a venturi type nozzle (one that provides hot or
cold air). This type of tool is capable of producing air stream temperatures down to -18°C (0°F) from one end
and 71°C (160°F) from the other. This is ideally suited for localized cooling needs.

Once the vehicle, component, or harness has been sufficiently cooled, manipulate the harness or components in
an effort to duplicate the concern.

TESTING FOR ELECTRICAL INTERMITTENTS

Perform the following procedures while wiggling the harness from side to side. Continue this at convenient
points (about 6 inches apart) while watching the test equipment.

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Testing for Short to Ground

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Testing for Continuity

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Testing for a Short to Voltage

If the fault is not identified, perform the procedure below using the MIN MAX feature on the J 39200 DMM.
This feature allows you to manipulate the circuit without having to watch the J 39200 . The J 39200 will
generate an audible tone when a change is detected.

1. Connect the J 39200 to both sides of a suspected connector (still connected), or from one end of a

suspected circuit to the other. Refer to Troubleshooting with a Digital Multimeter for information on
connecting the J 39200 to the circuit.

2. Set the rotary dial of the J 39200 to the V (AC) or V (DC) position.

3. Press the range button of the J 39200 in order to select the desired voltage range.

4. Press the MIN MAX button of the J 39200 . The J 39200 displays 100 ms RECORD and emits an

audible tone (beep).

5. Simulate the condition that is potentially causing the intermittent connection, either by wiggling the

connections or the wiring, test driving, or performing other operations. Refer to Inducing Intermittent
Fault Conditions .

6. Listen for the audible Min Max Alert which indicates that a new minimum or maximum value has been

recorded.

7. Press the MIN MAX button once in order to display the MAX value and note the value.

8. Press the MIN MAX button again in order to display the MIN value and note the value.

9. Determine the difference between the MIN and MAX values.

IMPORTANT: The J 39200 must be used in order to perform the following procedure since

the J 39200 can monitor current, resistance or voltage while recording the
minimum (MIN), and maximum (MAX) values measured.

IMPORTANT: The 100 ms RECORD mode is the length of time an input must stay at a

new value in order to record the full change.

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Wiring Systems - Hummer H2

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If the variation between the recorded MIN and MAX voltage values is 1 volt or greater an
intermittent open or high resistance condition exists. Repair the condition as necessary.

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If the variation between the recorded MIN and MAX voltage values is less than 1 volt an
intermittent open or high resistance condition does not exist.

SCAN TOOL SNAPSHOT PROCEDURE

Snapshot is a recording of what a control module on the vehicle was receiving for information while the
snapshot is being made. A snapshot may be used to analyze the data during the time a vehicle condition is
current. This allows you to concentrate on making the condition occur, rather than trying to view all the data in
anticipation of the fault. The snapshot contains information around a trigger point that you have determined.
Only a single data list may be recorded in each snapshot. The Scan Tool has the ability to store 2 snapshots.
The ability to record 2 snapshots allows comparing hot versus cold and good versus bad vehicle scenarios. The
snapshots are stored on a first-in, first-out basis. If a third snapshot is taken, the first snapshot stored in the
memory will be lost.

Snapshots can be 1 of 2 types:

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Snapshot - taken from the Snapshot menu choice

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Quick Snapshot - taken from the Data Display soft key choice, does not contain DTC information

When a snapshot is taken, it is recorded on the memory card and may contain as many as 1200 frames of
information. Because the snapshot is recorded onto the memory card, snapshots are not lost if the Scan Tool is
powered down.

The snapshot replay screen has a plot soft key that can be of great value for intermittent diagnosis. The snapshot
plot feature can help you to quickly determine if a sensor is outside of its expected values by plotting 3
parameters at a time. The data will be displayed both graphically and numerically showing the minimum and
maximum values for all frames captured. This is helpful, especially if the fault occurs only once and does not
set a DTC.

CIRCUIT PROTECTION - FUSES

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Wiring Systems - Hummer H2