Chart A-1, No Service Engine Soon Light - TORONADO & TROFEO: Notes

Fig 1: Chart A-1 & A-2, Wiring Schematic (Toronado & Trofeo)

Courtesy of GENERAL MOTORS CORP.

The SERVICE ENGINE SOON light is located in IPC. Light is powered by Ignition 1, circuit No. 39 and PCM completes system ground to turn light on. With ignition on and engine not running, light should be on. If with engine running, light is on steady, this indicates a fault code is set.

NOTE: Test numbers refer to numbers on diagnostic chart.

SERVICE ENGINE SOON light should be on.
Using a test light connected to battery voltage, probe each of the system ground circuits to be sure a good ground is present.