What fuse powers the heated oxygen sensor on the 5.8L Bronco?

A 15A fuse (position E) in the engine compartment fuse box, hot in run, feeding circuit 298 P/O (see Power Distribution page 13-4).

What does the MAP sensor do according to this diagram?

It measures atmospheric pressure for the PCM, which uses the information to adjust fuel/air ratio, transmission line pressure, and shift scheduling for higher altitude operation.

What wire colors are used for the MAP sensor circuits?

Circuit 359 GY/R (signal), 358 LG/BK, and 351 BR/W (via splice S163 and connector C185).

What is the HO2S signal wire circuit?

Circuit 74 GY/LB, running from the heated oxygen sensor through C1025/C1003/C103 and splice S165 to the PCM.

Where are the grounds for this circuit shown?

Circuit 57 BK grounds at G101 (or G100 depending on application); see Grounds page 10-3 or page 10-5.

Home/ Registry/ Ford/ Bronco/ 1992-1996/ “Buckin Bronco”/ Photo supermotors.net/registry/media/1137640

Ford Bronco 5.8L Engine Controls Wiring Diagram – MAP & O2 Sensor (Page 25-4)

Ford 25-4 Engine Controls 5.8L wiring diagram with MAP sensor and heated oxygen sensor circuits

‹ ›

Engine controls wiring diagram for 5.8L showing manifold absolute pressure sensor and heated oxygen sensor circuits to the PCM.

AI caption August 2018 · Photo 355 of 386

This is page 25-4 of a Ford factory-style wiring diagram set covering Engine Controls for the 5.8L engine, applicable to Bronco, Lightning, and F-Series trucks (with under-8500 lb and over-8500 lb GVW variants distinguished by asterisk footnotes). The diagram shows the Manifold Absolute Pressure (MAP) sensor (connector C1011) with a note explaining it measures atmospheric pressure for the PCM to adjust fuel/air ratio, transmission line pressure, and shift scheduling at altitude. It also shows the Heated Oxygen Sensor (HO2S), which provides a voltage related to exhaust oxygen content, powered through a 15A fuse (position E) in the engine compartment fuse box on circuit 298 P/O (hot in run). Signal circuits include 359 GY/R (MAP signal, also feeding the VIP Data Link Connector C198 and E4OD transmission on page 30-1), 358 LG/BK, 351 BR/W (return/ground via splice S163 and connector C185), 89 O (reference), and 74 GY/LB (HO2S signal to PCM pin 49). Ground is via 57 BK to G101/G100. PCM pins 45, 26, 46, 49, and 29 are shown. Cross-references point to Power Distribution page 13-4, Grounds pages 10-3/10-5, and E4OD Transmission page 30-1.

Is this accurate? Sign in to help verify it.

Frequently asked questions

What fuse powers the heated oxygen sensor on the 5.8L Bronco?: A 15A fuse (position E) in the engine compartment fuse box, hot in run, feeding circuit 298 P/O (see Power Distribution page 13-4).
What does the MAP sensor do according to this diagram?: It measures atmospheric pressure for the PCM, which uses the information to adjust fuel/air ratio, transmission line pressure, and shift scheduling for higher altitude operation.
What wire colors are used for the MAP sensor circuits?: Circuit 359 GY/R (signal), 358 LG/BK, and 351 BR/W (via splice S163 and connector C185).
What is the HO2S signal wire circuit?: Circuit 74 GY/LB, running from the heated oxygen sensor through C1025/C1003/C103 and splice S165 to the PCM.
Where are the grounds for this circuit shown?: Circuit 57 BK grounds at G101 (or G100 depending on application); see Grounds page 10-3 or page 10-5.