Ford Focus DCT Acceptable Grounding

On a 2012 Ford Focus with the Dual Clutch Transmission, DCT, with a Fluke 75 Digital Volt Meter, battery disconnected, I initially read 2.6 ohms from the battery negative cable, past the negative battery cable shunt, to the top transmission actuator. I scraped both test points before making the measurement. I cleaned the main body ground point and the two ground points under the air box with a file belt and wire wheel, cleaning the terminals, washers and nuts, grinding the paint off and putting it all back together with dielectric grease. I read 0.5 ohms after putting it back together. In my mind I thought this should be lower given the cable size.

The question is what is an acceptable grounding test for a Ford Focus or a modern vehicle?

• Is an ohm meter reading acceptable and what should I expect for a good connection?
• Should I put a current source on the cable and top of the transmission actuator measure the voltage drop? I am thinking just because I have a 0.5 ohm measurement, that doesn’t mean the path can handle significant current.
• Does Ford have a procedure for checking the ground connections?