Service Engine Soon

LED is controlled by Vehicle Control Module/Powertrain Control Module (VCM/PCM). As a check, LED illuminates when key is turned to RUN position. LED should turn off 1-5 seconds after engine starts. If a problem occurs in engine control system, PCM/VCM illuminates LED and a DTC may be stored. SERVICE ENGINE SOON light may be referred to as Malfunction Indicator Light (MIL).