Expo AWD L4-2350cc 2.4L SOHC 16 Valve (1993)
Central Power Supply: Service Precautions
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 ECM 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 ECM circuits and components.
TESTING PROCEDURES
Always follow recommended testing procedures. Never ground or apply voltage to a circuit unless specified by a testing procedure. ECM's
provide a regulated constant low voltage source to some circuits, which may require a minimum resistance (impedance) to operate. Directly
grounding or applying battery power to these circuits could damage the ECM and cause a system failure.
