4R70W Internal Wiring Harness 2009, new and ready to install. Fits the 4R70W. Ships fast from the USA.
A 2009 F-150 or E-150 that suddenly picks the wrong gear, will not lock the converter, or shifts with a hard bang, while the scan tool fills up with solenoid circuit codes, is a classic case for this part. This is a new internal wiring harness for the 2009 version of Ford's four-speed rear-drive overdrive, the transmission most parts catalogs still call the 4R70W and Ford's 2009 service literature calls the 4R75E. It is the soft, individual-wire harness that Ford brought back for 2009, with its own case connector and solenoid plugs.
From 1998 through 2008 these transmissions did not use a wire harness at all. ATSG's Wayne Colonna explains that Ford replaced it with a molded circuit board, the hard lead frame, in 1998, and that the lead frame developed its own run of electrical complaints. For 2009 every 4R75E went back to a soft internal wire harness, together with a new design of shift, TCC and EPC solenoids. Ford's service number for that 2009-up harness is 9L3Z-7G276-A. Colonna is clear that none of the 2009 parts retrofit to earlier models, which is why a 2005-2008 lead frame or a 1990s harness will not work here.
The PCM runs the transmission entirely through the circuits in this harness: shift solenoids 1/A and 2/B for gear selection, the torque converter clutch solenoid for lockup, the EPC solenoid for line pressure, and the transmission fluid temperature signal it uses to adjust shift timing. A single pinched or chafed wire can ground a solenoid circuit, pop a fuse and leave the truck with no electronic control at all.
Ford issued a bulletin, summarized by Motor Age, for some 2009 F-150, E-150, Crown Victoria, Grand Marquis and Town Car vehicles with a 4R75E built before 12/1/2008. The cause was an internal harness routed so it got pinched between the pan and the main control. The symptoms listed are:
Check the build date on the transmission tag. On a unit built before 12/1/2008 with these symptoms, the bulletin calls for dropping the pan and inspecting the harness routing for pinch damage. On any 2009 unit, check fuse F79 first, then test the solenoid circuits through the case connector. The Sonnax testing booklet prints a separate 2009-and-later case connector layout, so do not use the 1998-2008 pin chart. A circuit that reads short to ground or open at the connector but tests correctly at the solenoid confirms the harness. Our 4R70W F-150 shift problems guide covers the gear-by-gear symptoms, and the shift problems guide for the full-size SUVs walks through the same solenoid and pressure checks.
This listing is for 2009 transmissions. That covers the 4.6L 2009 F-150 and the 2009 E-150 named in Ford's bulletin, and the 2009 Panther cars use the same soft-harness design. Model year alone is not a perfect guide on transmissions built in late 2008, so look at your old part: if you have a molded plastic lead frame, this is not your part. Match the case connector shape and solenoid plugs to the photo, or send us your year and VIN to verify. The 4R70W collection page lists the rest of the parts for this family.
If the harness short has been there a while, the transmission may have slipped or run without lockup long enough to damage frictions. Burnt fluid or debris in the pan means the 4R75W overhaul kit for 2003-2014 is the better buy. During a rebuild, note that ATRA's interchange notes call for the non-magnetic 2004-up sun shell so the speed sensor reads correctly.
| Fits | 4R70W 2009 |
| Part type | Internal Wiring Harness |
| Condition | New |
| 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. Ford went back to a soft wire harness with redesigned solenoids for 2009, and ATSG notes none of those parts interchange with earlier models. A 2009 unit needs the 2009-style harness and connector.
Quite possibly. Ford's bulletin for 2009 F-150 and E-150 trucks with a 4R75E built before 12/1/2008 blames a harness pinched between the pan and the main control, which shorts solenoid circuits and can open fuse F79. Check the build date and inspect the routing with the pan down.
Yes. By 2009 Ford called this transmission the 4R75E, while many catalogs still list it under 4R70W. What matters is the 2009 soft-harness design, Ford service number 9L3Z-7G276-A, and matching the case connector.
Use what your owner guide or dipstick specifies. Ford's 2009 Crown Victoria owner guide lists MERCON LV for the 4R75E. Do not assume MERCON V from older 4R70W information.
Test them first. If the harness was shorted, a solenoid can be damaged too. Any solenoid outside its resistance range or sticking should be replaced while the pan is off, using 2009-style solenoids only.
