Proper Tools and Testing Procedures
DIGITAL VOLT/OHM METERUse a Digital Volt-Ohm Meter (DVOM) with a minimum 10 mega-ohms internal impedance when testing an Electronic Control Module or related component, unless use of an analog meter is specified by a test procedure.
Analog meters have low internal impedance and will "load" low voltage circuits, resulting in inaccurate measurements and possible damage to components.
TESTING PROCEDURES
^ Always follow recommended testing procedures.
^ Never ground or apply voltage to a circuit, unless specified by a test procedure. Directly grounding or applying battery power to a circuit may damage the circuit and/or components.