Calais V6-3300 3.3L MFI VIN N (1990)
Malfunction Indicator Lamp: Testing and Inspection
Chart A-1
Chart A-1 Wiring Diagram
CIRCUIT DESCRIPTION:
There should always be a steady "SERVICE ENGINE SOON" light when the ignition is "ON" and engine stopped. Ignition voltage is supplied to the
light bulb. The ECM will control the light and turn it "ON" by providing a ground path through CKT 419 to the ECM.
