Ford Bronco 5.8L California Engine Controls Wiring Diagram - IAT, HO2S, PCM (25-10)

This is page 25-10 of a Ford factory-style wiring diagram covering Engine Controls for the 5.8L (351) engine with California emissions. The diagram shows the circuits for the Intake Air Temperature (IAT) sensor, the Data Link Connector (DLC), and the right-hand Heated Oxygen Sensor (HO2S) as they connect to the Powertrain Control Module (PCM). A callout explains that the IAT sensor is a thermistor that decreases resistance as intake air temperature increases, and that the PCM uses the voltage drop to calculate idle fuel delivery, spark timing and EGR control. Another callout explains the HO2S provides a voltage related to exhaust oxygen content for air/fuel ratio regulation. Power for the HO2S heater comes from a 15A fuse (position E) in the engine compartment fuse box, hot in run, on circuit 298 P/O (12V in RUN). Key circuits include 359 GY/R (signal return/reference), 743 GY (IAT signal to PCM pin 25), 351 BR/W (to PCM pin 26), 74 GY/LB (HO2S signal to PCM pin 44), and 57 BK to ground G101 via splice S100. Connectors shown include C101, C103, C107, C164, C185, C198F, and C1025. Cross-references point to page 25-11, Power Distribution page 13-4, and Grounds page 10-2.