PCM Service Precautions

Electrical Testing Precautions

The PCM is designed to withstand normal current draws associated with vehicle operations, however, care must be used to avoid overloading any of these circuits. In testing for opens or shorts do not ground or apply voltage to any of the PCM circuits unless instructed to do so by the diagnostic procedures. These circuits should only be tested using the Digital Multimeter J 39200.

Note: Whenever a PCM removal and replacement is performed, follow the procedures in this database.

Electrostatic Discharge Damage

The electronic components used in the control systems are often designed in order to carry very low voltage. The 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. Use care when handling and testing the electronic components.


Aftermarket (ADD-ON) Electrical And Vacuum Equipment

Aftermarket (Add-on) Electrical and Vacuum Equipment is defined as any equipment installed on a vehicle after leaving the factory where the vehicle was originally assembled that connects, in any way, to the vehicles electrical or vacuum systems. No allowances have been made in the design of this vehicle for this type of equipment. Therefore, addition of aftermarket equipment must be done with the utmost care for the vehicle.