Field notes

Restoration guides, technical breakdowns and pump system know-how.

What a full ACD/AYC pump rebuild involves, what gets replaced, and why bench testing under load is the stage that matters.

Warning lights, the ignition-on self-test, and how to tell a failing ACD/AYC pump from a sensor or fluid fault.

How Mitsubishi's Active Center Differential works, which Lancer Evolution models actually have it, and why US-market cars differ.