5R110W Internal Wiring Harness, remanufactured and ready to install. Fits the 5R110W. Ships fast from the USA.
If your Super Duty, Excursion or E-Series van with the 5R110W TorqShift keeps throwing a handful of solenoid or temperature codes at once, drops into limp mode on a bump, or flashes the Tow/Haul lamp and then acts normal after a restart, the wiring inside the pan is a common place for that kind of intermittent fault to live. This is a remanufactured internal wiring harness for the 5R110W, the piece that carries every electrical signal between the case connector and the parts bolted inside the transmission.
The 5R110W has no shift valves in the usual sense. The solenoid body bolted to the bottom of the case holds seven variable-force solenoids, and the computer runs every clutch except the forward clutch by varying current to its own solenoid between 0 and 1 amp. That means the transmission is only as good as the copper feeding those solenoids. The internal harness runs from the round pass-through connector in the case to each solenoid, to the pressure switches on bodies that have them, to the transmission fluid temperature (TFT) sensor and to the internal transmission range (TR-P) sensor. On the original design the natural-colored plugs go to the solenoids and the black plugs go to the pressure switches. The turbine and intermediate shaft speed sensors and the output speed sensor are mounted on the outside of the case, so they are not part of this harness.
Do not condemn the internal harness until the outside wiring has been cleared. On the 6.0L trucks, Transmission Digest documented an F-350 with a full spread of pressure control codes that turned out to be diesel fuel leaking from the water-in-fuel sensor, wicking up the C138E harness and filling the computer. Inspect the external harness and the case connector for chafing, oil and corrosion first. Then measure each solenoid through the pass-through connector and again directly at the solenoid with the pan off. If the solenoid reads good at its own terminals but open, shorted or intermittent through the case connector, the harness is the fault. Our 5R110 shift solenoid symptoms and testing guide walks through the solenoid functions and the codes each one sets.
This listing is for the 5R110W TorqShift used in 2003-2010 Ford F-250, F-350, F-450 and F-550 Super Duty trucks with the 6.0L or 6.4L Power Stroke and gas V8/V10, the Excursion and E-Series vans. Ford changed the solenoid body during the run. Sonnax notes that original bodies used one or five pressure switches depending on model year and that Ford dropped the switches in late 2004, so harness layouts are not identical across years. Lay your old harness next to the photo and match the connector count and positions, or send us your year and VIN before ordering. You can compare other years on our 5R110W parts page, including the separately listed 2003-2017 internal harness.
Drain the fluid and drop the pan and filter. Unplug each solenoid, switch, TFT and range sensor connector and note the routing and every retaining clip before pulling the old harness. Release the case connector retainer and push the pass-through into the case. Install the new harness with a good seal on the case connector, follow the factory routing, and make sure no wire can be pinched by the pan rail or touch a moving part. This is a good time to install a fresh 5R110W filter kit, and if the pan has been damaged a replacement oil pan with drain plug makes future service easier. Refill with the fluid Ford calls for on your VIN. These units were released on MERCON SP and Ford later authorized MERCON LV for complete refill and top-off. If the battery was disconnected, run Ford's engagement relearn: warm the fluid to 130 F on TFT, then five engagements each of Park to Reverse, Drive to Reverse, Reverse to Drive and Neutral to Drive, five seconds apart.
| Fits | 5R110W |
| Part type | Internal Wiring Harness |
| Condition | Remanufactured |
| Brand | OEM |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. On the 5R110W the turbine and intermediate shaft speed sensors share one housing mounted on the outside of the case, and the output speed sensor sits on the extension housing. The internal harness connects the case connector to the solenoids, pressure switches, TFT sensor and range sensor inside the pan.
Early solenoid bodies carried pressure switches that Ford dropped in late 2004, so harness layouts vary. Compare the connector count and positions on your old harness with this one, or send your year and VIN and we will confirm before it ships.
Measure the solenoid at its own terminals with the pan off, then measure the same circuit through the case pass-through connector. A good solenoid that reads open, shorted or intermittent through the connector points to the harness.
Most of the harness is reached with the pan and filter removed, since it plugs into the solenoid body and range sensor from below. Route it exactly like the original and refit every retaining clip.
The 5R110W was released on MERCON SP, and Ford later authorized MERCON LV for complete refill and top-off. Confirm the callout for your VIN in Ford service information.
