Envoy 4WD V8-5.3L VIN P (2004)
The fuse is the most common method of an automotive wiring circuit protection. Whenever there is an excessive amount of current flowing through a
circuit the fusible element will melt and create an open or incomplete circuit. Fuses are an one time protection device and must be replaced each time the
circuit is overloaded. To determine if a fuse is open, remove the suspected fuse and examine the element in the fuse for an open (2). If not broken (1),
also check for continuity using a DMM or a continuity tester. If the element is open or continuity is suspect, replace the fuse with one of equal current
rating.
Circuit Protection - Fusible Links
CIRCUIT PROTECTION - FUSIBLE LINKS
Fusible link is wire designed to melt and break continuity when excessive current is applied. It is often located between or near the battery and starter or
electrical center. Use a continuity tester or a DMM at each end of the wire containing the fusible link in order to determine if it is broken. If broken, it
must be replaced with fusible link of the same gage size.
Repairing a Fusible Link
IMPORTANT: Fusible links cut longer than 225 mm (approximately 9 in) will not provide sufficient overload protection.
Refer to Splicing Copper Wire Using Splice Clips.
Flat Wire Repairs
FLAT WIRE REPAIRS
NOTE: The flat wire within the flex wiring harness is not serviceable. If an open or short exists within the flex wiring harness the complete harness
must be replaced.
Heated Oxygen Sensor (HO2S) Wiring Repairs
HEATED OXYGEN SENSOR (HO2S) WIRING REPAIRS
TOOLS REQUIRED
J 38125-C Terminal Repair Kit
NOTE: Do not solder repairs under any circumstances as this could result in the air reference being obstructed.
If the heated oxygen sensor pigtail wiring, connector, or terminal is damaged the entire oxygen sensor assembly must be replaced. Do not attempt to
repair the wiring, connector, or terminals. In order for the sensor to function properly it must have a clean air reference. This clean air reference is
obtained by way of the oxygen sensor signal and heater wires. Any attempt to repair the wires, connectors or terminals could result in the obstruction of
the air reference and degrade oxygen sensor performance.
The following guidelines should be used when servicing the heated oxygen sensor:
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Do not apply contact cleaner or other materials to the sensor or vehicle harness connectors. These materials may get into the sensor, causing poor
performance. Also, the sensor pigtail and harness wires must not be damaged in such a way that the wires inside are exposed. This could provide a
path for foreign materials to enter the sensor and cause performance problems.
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Neither the sensor nor vehicle lead wires should be bent sharply or kinked. Sharp bends, kinks, etc., could block the reference air path through the
