Quote Originally Posted by sambb View Post
You'll get that N75 error if its unplugged ie the ECU sees an open circuit at the N75 plug terminals or within the solenoid thats plugged to it. Check that the solenoid is 30 ohms, and that at the plug that the pin associated with the blue/black wire is 0 ohms to rocker cover earth, and the other pin is O/C to earth. Also check that between plug pins you get O/C to confirm no shorts are within the loom or back at the ECU output. If that all looks good ( and assuming its not an intermittent partial O/C within the solenoid itself) then I'd put my money on dry joints from plug-solenoid. Spray them with CRC contact cleaner and reseat the plug a few times and then some 2-26 or WD.
Thanks Sam, really appreciate the detailed response. Will put that into action.