1996 Ford 5.8L Engine Controls Wiring Diagram - MIL & O2 Sensor Circuits 25-5

This is page 25-5 of a 1996 Ford wiring diagram set (EVTM style), covering Engine Controls for the 5.8L engine, under 8500 GVW. The diagram shows the Malfunction Indicator Lamp (MIL) circuit and the heated oxygen sensor (HO2S) circuits. Power comes from fuse 17 (10A) in the fuse panel (hot in start or run) through circuit 640 R/Y and splice S215 to the instrument cluster's MIL, then via circuit 658 PK/LG through connectors C202F/C202M to the Powertrain Control Module (PCM). A callout explains the MIL lights with the ignition switch ON prior to cranking, goes off when the engine starts, and is turned back on by the PCM if a fault develops. Two heated oxygen sensors are shown: HO2S #12 (connectors C1069F/C1069M) and HO2S #21 (connectors C1028F/C1028M), fed by circuits 359 GY/R (GN/R) and 361 R, with signal circuits 392 R/LG, 393 W/BK, 388 V/LB, and 94 R/BK returning to the PCM through splices S146, S169, S125, S126 and connectors C110, C101M, and C1027. Cross-references point to Power Distribution (page 13-11), Fuse Panel (pages 13-19), Instrument Cluster (page 60-3), and Transmission Controls E4OD (pages 30-1, 30-2).