Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la
If it fails: lemon-manuals.org.ua

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Proper Tools and Testing Procedures

DIGITAL VOLT/OHM METER
Use 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.