SW L4-1.9L DOHC VIN 7 (1993)
Malfunction Indicator Lamp: Description and Operation
Indicator Lamps
The SERVICE ENGINE SOON indicator lamp is pulled to by the powertrain control module (PCM). When the lamp is pulled to ground, current from
the ignition circuit flows through the indicator lamp, allowing it to illuminate. This indicates to the vehicle's operator that there is a possible problem with
the engine control system.
During engine start-up the SERVICE ENGINE SOON indicator lamp is illuminated, for approximately two seconds, by the PCM for a bulb check.