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In that sense it can be considered a continuity tester I guess, but the purpose is test resistance. As explained a conitnuity tester only give a yes or no. Ohms test give you a measurment. When coil windings and brushes in motors start to wear the gap between the forces that make the motor operate become larger the resistance increases. Once the resistance reaches a certain point, the motor is considered bad and needing replacement. You can also measure resistance on sensors too. For example a Throttle position sensor should be XX resistance at part throttle, and a differant resistance at WOT (Wide Open Throttle) By the resistance measurement that is fed back to the ECM, that is how the ECM knows what to tell other components to do, like adjust or advance ignition timing or lean or richen the fuel mixture. If the TPS is givng bad resistance readings to the ECM, then the ECM is going to tell the other components to do the wrong things. The ECM also knows what range of resistance should be for each sensor, and once they get outside that range is when the Check Engine light will come on because of a thrown code. Also some sensors are checked using milivolts so its required to use a digital multimeter to test those. TPS may even be in volts, I just used it as an example. About the only time I use an ohm meter is when I am testing something to be good or bad as far as current draw, not to check for continuity. Many times in an ohms test you get that ever so bad infinate reading, then you know something is way out of range or a broken circuit somewhere.
