Engine Control Module: Service Precautions

CONTROL MODULE SERVICE PRECAUTIONS
The control module is designed to withstand normal current draws associated with vehicle operations. Avoid overloading any circuit. When testing for opens or shorts, do not ground any of the control module circuits unless instructed. When testing for opens or shorts, do not apply voltage to any of the control module circuits unless instructed. Only test these circuits with a digital voltmeter J 39200, while the control module connectors remain connected to the control module.

USE OF CIRCUIT TESTING TOOLS
You should not use a test light to diagnose the powertrain system. You should know how to use jumper wires to test components and allow DVM readings without damaging terminals. You should know how to use Connector Test Adapter Kit, J 35616 and use it whenever diagnostic procedures call for front probing any connector.

ELECTROSTATIC DISCHARGE DAMAGE

CAUTION: 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 in order to carry very low voltage. Electronic components are susceptible to damage caused by electrostatic discharge. Less than 100 volts of static electricity can cause damage to some 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. Static charges can cause damage; therefore, it is important to use care when handling and testing electronic components.