LEMON Manuals: Even more car manuals for everyone
Home >> Cadillac >> 1991 >> Seville Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes >> Diagnostic Tests >> PFI Chart A-1, Inoperative Service Engine Soon Light

PFI Chart A-1, Inoperative Service Engine Soon Light

The SERVICE ENGINE SOON light is controlled by the PCM and will turn on 2 seconds when ignition switch in turned to the RUN position. When engine is cranked, SERVICE ENGINE SOON light will be off. After the key is returned to RUN position, SERVICE ENGINE SOON light will turn on another 2 seconds.

NOTE: Test numbers refer to test numbers on diagnostic chart.
  1. Terminals D1, D6, D7 and A12 are PCM ground. Terminals B1 and C16 are battery positive to the PCM. The PCM will function only one power and ground connection, but all should be tested.
Fig 1: PFI Chart A-1, Schematic, Inop. Service Engine Soon Light
G91D09342
Fig 2: PFI Flow Chart A-1, Inop. Service Engine Soon Light
GB0022483