Field Service Mode Check (If Available)

If DLC test terminal "B" is grounded with engine running, SERVICE ENGINE SOON light will indicate operational mode of engine. This test confirms proper operation of fuel system and verifies "closed loop" operation. Clear codes and perform this test after any repair is completed. Some models require the use of a scan tester to enter field service mode. Field service mode check can be found by proceeding to FIELD SERVICE MODE CHECK in BASIC TESTING article in this section.