Electronic Component Handling

ELECTRICAL/ELECTRONIC TESTING
Do not disconnect or connect electrical connectors with ignition switch in the ON position--unless specifically instructed in procedure.

Do not connect test equipment directly to Engine Control Module (ECM) except where noted.

When measuring voltage at control module harness connectors disconnect harness connector with ignition OFF then turn ignition ON as necessary.

To prevent deforming control unit harness connectors do not probe terminals directly. Insert pin(s) from the harness side and perform measurements through pin(s).

Do not attempt to measure oxygen sensor output as sensor will be damaged.

Do not probe wires through insulation damage to the insulation can lead to corrosion of the wire and cause system failure.

ELECTRONIC CONTROL MODULE PRECAUTIONS
Do not try to disassemble any electronic control module.

Before performing electrical welding (for instance spot welding) disconnect the battery radio and all electronic control modules.

If temperatures will exceed 80°C (176°F) (example: infra-red spray booth) remove all control modules.

Avoid getting water on any electronic components.

Never apply battery power to a component unless directed to do so in a test procedure.

STATIC DISCHARGE
Automotive computer systems are designed to operate at 3-5 Volts and are susceptible to damage by voltages as low as 12 volts. It takes up to 4,000 volts of static discharge for a person to feel the "ZAP". The two most common ways to become statically charged are explained below.

Charging By Friction
Friction between organic materials (such as cotton or leather) and synthetics (such as plastic, vinyl, or glass) can generate up to 25,000 volts. Can be accomplished by sliding across a car seat or by wearing a cotton shirt under a synthetic coat.

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.

Discharging Static
Discharge static by touching ground or maintaining a ground connection to a bare skin area like the wrist before handling electronic parts.

Never touch electronic control module connector pins, integrated circuit connector pins, or soldered components on circuit boards.