D4: Check Harness GND Continuity

Measure the resistance between EM013/027 and PI026/002
Repeat for EM013/027 and PI027/002

- Is the resistance < 0.5 ohms?
Yes
GO to D5 D5: Check Harness Circuit Continuity
No
Inspect connectors EM013 and PI026 for corrosion, damaged or pushed back pins or repair the harness/connector PI001/018. Test the system for normal operation.