Innova 3100 Owner's Manual page 7

Safety Precautions
SAFETY FIRST!
To prevent damage to the on-board computer when taking
vehicle electrical measurements, always use a digital
multimeter with at least 10 megOhms of impedance.
The vehicle's battery produces highly flammable hydrogen
gas. To prevent an explosion, keep all sparks, heated items
and open flames away from the battery.
Don't wear loose clothing or jewelry when working on an
engine. Loose clothing can become caught in the fan,
pulleys, belts, etc. Jewelry is highly conductive, and can
cause a severe burn if it makes contact between a power
source and ground.
OBD 2 5