LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 1994 >> SC 300 Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Acoustic Control Induction System (ACIS) >> ACIS Circuit
April 5, 2026: LEMON Manuals is launched! Read the announcement.

ACIS Circuit

  1. Check ACIS Vacuum Switching Valve (VSV). See Figure. See ACIS VACUUM SWITCHING VALVE (VSV) . If VSV is okay, pull back the right front floor mat. Remove ECM protective cover. Connect a Check Harness (09990-01000) between ECM and harness. See USING CHECK HARNESS  under INTRODUCTION. Turn ignition on.
  2. Measure voltage between chassis ground and terminal No. 39 of ECM connector "B" (Green/Red wire). To identify ECM connectors and terminals, see Figure.
  3. If battery voltage is present, check for faulty vacuum tank or hoses. See ACIS VACUUM TANK . If battery voltage is not present, check for open or shorted circuit between EFI main relay and ECM. If circuit is okay, replace ECM.
scientia non olet · About LEMON Manuals