O2: Check Harness Core to Core Insulation

With EM010, EM011, PI006 & PI042 disconnected, measure the insulation resistance between EM010/021 & EM010/020
Repeat for EM011/012 & EM011/008
Repeat for EM011/011 & EM011/010

All resistances > 10M ohms?

Yes
Go to P1

No
Inspect EM010, & EM011 for corrosion, bent/pushed back pins or locate & repair the harness/connector PI001.
Go to O3