Bad Earth Query

Code 93 has popped up again ( quad drive module )
Alot of research has pointed towards a bad earth

I've managed to check all of the ecu earth via autodata ( checking the resistance on the pins and they are all ok )

As for the engine loom its different, should the resistance be the same as the ecu pin resistance 0.0v ?

I've just checked the gearbox earth and it is 0.0v but the alternator and block earth is showing 0.07, should all of the earths be 0.0v , the block and alternator are painted so maybe its worth cleaning the areas up and see if it makes a difference.

Just wanted some advice on the earth resistance to see if it makes sense

The engine has also starting fluctuating the revs recently