What fuses power the PCM and fuel pump circuits on the 4.9L?

Three 20A fuses in the engine compartment fuse box: one hot in start or run (feeding the PCM power diode via circuit 16 R/LG) and two hot at all times (feeding the PCM power relay and fuel pump relay via circuit 37 Y).

What wire color and circuit feeds the fuel pump / inertia switch?

Circuit 238 DG/Y (dark green/yellow) from the fuel pump relay output runs through splice S139 and connectors C202 and C185 to the inertia fuel shutoff on page 23-7.

What circuit does the PCM power relay energize?

Circuit 361 R (red), which carries 12V (relay energized) to the PCM, the fuel pump relay coil, the E4OD transmission (page 30-2), and connector C101 (page 23-2).

How is the PCM grounded in this diagram?

Through circuits 57 BK and 570 BK/W, via splices S102 and S106 to grounds G100, G101, and G104 (see grounds pages 10-1 and 10-3).

What does the PCM do according to this diagram?

It receives inputs from various sensors and uses the information to control fuel flow, Exhaust Gas Recirculation (EGR), ignition, transmission controls (with E4OD), and evaporative emissions.

Home/ Registry/ Ford/ Bronco/ 1992-1996/ “Buckin Bronco”/ Photo supermotors.net/registry/media/1137622

Ford Bronco 4.9L Engine Controls Wiring Diagram - PCM & Fuel Pump Relay (23-1)

Ford 23-1 Engine Controls 4.9L wiring diagram with PCM power relay, fuel pump relay, fuse box

‹ ›

Engine controls wiring diagram for 4.9L showing PCM power relay, fuel pump relay and powertrain control module circuits.

AI caption August 2018 · Photo 337 of 386

This document is page 23-1 of an engine controls wiring diagram for a Ford vehicle equipped with the 4.9L inline-six engine. It shows the power distribution and ground circuits for the Powertrain Control Module (PCM) and the fuel pump. Three 20-amp fuses in the engine compartment fuse box supply the circuit: one hot in start or run (feeding circuit 16 R/LG through the PCM power diode to 175 BK/Y) and two hot at all times (feeding circuit 37 Y to the PCM power relay and fuel pump relay). The PCM power relay directs 12V to the PCM, fuel pump relay, and related components via circuit 361 R, which also feeds the E4OD transmission (page 30-2) and connector C101 (page 23-2). The fuel pump relay output on circuit 238 DG/Y routes through splice S139 and connectors C202 and C185 to the inertia fuel shutoff switch (page 23-7). Circuit 926 LB/O feeds the VIP data link connector at C198. PCM grounds are shown via circuits 57 BK and 570 BK/W through splices S106 to grounds G100, G101, and G104. A callout explains the PCM receives sensor inputs to control fuel flow, EGR, ignition, transmission (E4OD), and evaporative emissions.

Is this accurate? Sign in to help verify it.

Frequently asked questions

What fuses power the PCM and fuel pump circuits on the 4.9L?: Three 20A fuses in the engine compartment fuse box: one hot in start or run (feeding the PCM power diode via circuit 16 R/LG) and two hot at all times (feeding the PCM power relay and fuel pump relay via circuit 37 Y).
What wire color and circuit feeds the fuel pump / inertia switch?: Circuit 238 DG/Y (dark green/yellow) from the fuel pump relay output runs through splice S139 and connectors C202 and C185 to the inertia fuel shutoff on page 23-7.
What circuit does the PCM power relay energize?: Circuit 361 R (red), which carries 12V (relay energized) to the PCM, the fuel pump relay coil, the E4OD transmission (page 30-2), and connector C101 (page 23-2).
How is the PCM grounded in this diagram?: Through circuits 57 BK and 570 BK/W, via splices S102 and S106 to grounds G100, G101, and G104 (see grounds pages 10-1 and 10-3).
What does the PCM do according to this diagram?: It receives inputs from various sensors and uses the information to control fuel flow, Exhaust Gas Recirculation (EGR), ignition, transmission controls (with E4OD), and evaporative emissions.