Lumina V6-3.1L VIN J (2000)
Equivalents - Decimal And Metric (Part 2 Of 2)
Metric Fasteners
This vehicle is dimensioned in the metric system. Most metric fasteners are very close in diameter to well known fasteners in the English (inch)
system. Replace fasteners with those of the same nominal diameter, thread pitch, and strength.
A number marking identifies the OE metric fasteners (except cross-recess head screws). The number also indicates the strength of the fastener
material. A Posidrive(R) or Type 1A cross-recess identifies a metric cross-recess screw. For best results, use a Type 1A cross-recess screwdriver, or
equivalent, in Posidrive(R) recess head screws.
GM Engineering Standards and North American Industries have adopted a portion of the ISO-defined standard metric fastener sizes. The purpose was
to reduce the number of fastener sizes used while retaining the best thread qualities in each thread size. For example, the metric M6.0 X 1 screw, with
nearly the same diameter and 25.4 threads per inch replaced the English 1/4-20 and 1/4-28 screws. The thread pitch is midway between the English
coarse and fine thread pitches.
Basic Knowledge Required
Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures contained in this section. You should understand the basic
theory of electricity and know the meaning of voltage (volts), current (amps) and resistance (Ohms). You should understand what happens in a circuit
with an open or a shorted wire. You should be able to read and understand a wiring diagram.
Refer to Strategy Based Diagnosis in General Information in order to properly diagnose and repair the customer concern.
Checking Aftermarket Accessories
Do not connect aftermarket accessories into the following circuits:
CAUTION: REFER TO SIR SERVICE PRECAUTIONS CAUTION IN SERVICE PRECAUTIONS.
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SIR circuits, all such circuits are indicated on circuit diagrams with the SIR symbol.
