Engine Control Module: Service Precautions

PCM Service Precautions
The control module is designed to withstand normal current draws associated with vehicle operations. Avoid overloading any circuit. When testing for the opens or the shorts, do not ground or apply voltage to any of the control module circuits unless instructed to do so. These circuits should only be tested using a digital voltmeter J 39200. The control module connectors should remain connected to the control module while testing.

Electrostatic Discharge (ESD) Damage
In order to prevent possible Electrostatic Discharge damage to the PCM, Do Not touch the connector pins or the soldered components on the circuit board.

Electronic components used in the control systems are often designed to operate at very low voltages. Electronic components are susceptible to damage caused by electrostatic discharge. Less than 100 volts of static electricity can cause damage to some of the electronic components. There are several ways for a person to become statically charged. The most common methods of charging are by friction and by induction. An example of charging by friction is a person sliding across a car seat. Charging by induction occurs when a person with well insulated shoes stands near a highly charged object and momentarily touches ground. Charges of the same polarity are drained off leaving the person highly charged with the opposite polarity. Therefore, it is important to use care when handling and testing electronic components to avoid electrostatic charges that can cause electronic component damage.