FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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Proper Tools and Testing Procedures

SCAN TOOLS
Not all SCAN testers are compatible with every system. A SCAN tool that produces faulty readings should NOT be used, and the problem should be reported to the tool manufacturer. Use of a faulty SCAN tool can result in improper diagnosis and unnecessary component replacement. Follow the proper instructions, located in the owners manual, for the specific SCAN tool being used.

DIGITAL VOLT / OHM METER
Use a digital volt / ohm meter (DVOM) with a minimum 10 mega-ohms internal impedance when testing a Control Module or related components, unless use of an analog meter is specified by a testing procedure. Analog meters have low internal impedance and cause circuit "loading" in low voltage circuits, resulting in inaccurate measurements and possible damage to components. Use of a DVOM is necessary to obtain accurate measurements and avoid damaging low voltage Control Module circuits and components.

TESTING PROCEDURES
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
Do not use a test lamp in order to diagnose the Powertrain electrical systems unless specifically instructed by the diagnostic procedures. Use the Connector Test Adapter Kit, J 35618 whenever diagnostic procedures call for probing any connectors.