How do I fix PV String Not Connected (PVS_a018_MciString A-D) on a Tesla?

Verify the string DC connectors are fully seated. Then: Measure string Voc and polarity at the input.

Tesla

PVS_a018_MciString

PV String Not Connected (PVS_a018_MciString A-D)

PV string controller reports a string not detected on its MCI input (Powerwall 3 / Powerwall+).

Common causes

DC connectors not seatedString faultMCI input fault

What to check

STEP 1

Verify the string DC connectors are fully seated.

STEP 2

Measure string Voc and polarity at the input.

Escalate if

String tests healthy but input still reads disconnected

Need full interactive diagnosis?

Faultpath walks you through decision trees, fault codes, and commissioning — built for solar & battery engineers.