Wiring Systems to perform the following inspections:
z
Inspect for poor mating of the connector halves, or terminals improperly
seated in the connector body.
z
Inspect for improperly formed or damaged terminals. Test for poor terminal
tension.
z
Inspect for poor terminal to wire connections including terminals crimped
over insulation. This requires removing the terminal from the connector
body.
z
Inspect for corrosion/water intrusion. Pierced or damaged insulation can
allow moisture to enter the wiring. The conductor can corrode inside the
insulation, with little visible evidence. Look for swollen and stiff sections
of wire in the suspect circuits.
z
Inspect for wires that are broken inside the insulation.
z
Inspect the harness for pinched, cut or rubbed through wiring.
z
Ensure that the wiring does not come in contact with hot exhaust
components.
Control Module
Power and Grounds
Component Power
and Grounds
Poor power or ground connections can cause widely varying symptoms.
z
Test all control module power supply circuits. Many vehicles have multiple
circuits supplying power to the control module. Other components in the
system may have separate power supply circuits that may also need to be
tested. Inspect connections at the module/component connectors, fuses, and
any intermediate connections between the power source and the
module/component. A test lamp or a DMM may indicate that voltage is
present, but neither tests the ability of the circuit to carry sufficient current.
Ensure that the circuit can carry the current necessary to operate the
component. Refer to Circuit Testing and Power Distribution Schematics
in Wiring Systems.
z
Test all control module ground and system ground circuits. The control
module may have multiple ground circuits. Other components in the system
may have separate grounds that may also need to be tested. Inspect grounds
for clean and tight connections at the grounding point. Inspect the
connections at the component and in splice packs, where applicable. Ensure
that the circuit can carry the current necessary to operate the component.
Refer to Circuit Testing and Ground Distribution Schematics in Wiring
Systems.
Temperature
Sensitivity
z
An intermittent condition may occur when a component/connection reaches
normal operating temperature. The condition may occur only when the
component/connection is cold, or only when the component/connection is
hot.
z
Freeze Frame, Failure Records, Snapshot, or Vehicle Data Recorder data
may help with this type of intermittent condition, where applicable.
z
If the intermittent is related to heat, review the data for a relationship with
2004 Hummer H2
2004 ENGINE PERFORMANCE Engine Controls (Troubleshooting) - 4.8L, 5.3L, and 6.0L - Hummer H2