Static Discharge

PRECAUTIONS
^ Discharge any static electrical charges before handling sensitive parts. Touch ground or maintain a ground connection to a bare skin area like the wrist when servicing sensitive parts

^ Never touch Electronic Control Unit connector pins, integrated circuit connector pins, or soldered components on Electronic Control Unit circuit boards.

STATIC DISCHARGE
Electronic components used in automotive computers are designed to operate at low voltages (3 - 5 volts) and are extremely susceptible to damage caused by static electrical discharge. Voltages as low as 12 volts can damage computer circuits. By comparison, it takes as much as 4,000 volts of static discharge for a person to even feel the "ZAP" and there is no way of knowing whether the charge is positive or negative in nature.
Static charges are gradually equalized by moisture in the air, but are retained much longer when humidity is low. Use care when handling and testing electronic components.
There are several ways in which a person can become statically charged. Charging by friction and charging by induction are the most common.

CHARGING BY FRICTION
Friction between organic materials (such as cotton or leather) and synthetics (such as plastic, vinyl, or glass) will generate static charges as great as 25,000 volts. This can happen by simply sliding across a car seat or by wearing a cotton shirt under a coat made of synthetic materials.

CHARGING BY INDUCTION
Charging by induction occurs when a person standing near a highly charged object (strong magnetic field such as a transformer) momentarily touches ground. Like charges are displaced to ground, leaving the person highly charged with opposite polarity.