5R55S Governor Pressure Solenoid, new other (see details) and ready to install. Fits the 5R55S. Ships fast from the USA.
If you searched for a 5R55S governor pressure solenoid, you were probably chasing a flare between gears, a hard bang into Drive, or a 2005-2010 Mustang V6 or Lincoln LS stuck in limp mode. The 5R55S does not have a governor pressure solenoid; that part name comes from Chrysler's older RE transmissions. The 5R55S does all of that work with one solenoid pack bolted to the valve body, and that pack is what this listing is: a genuine OEM Ford 5R55S/5R55W solenoid pack that was removed from a working transmission and had every solenoid function-checked before it was put on the shelf. It is a used, tested unit, not a new one.
Transmission Digest counts eight solenoids in the S and W pack: four on/off shift solenoids, one pulse width modulated converter clutch solenoid and three variable force solenoids. In an older governed transmission, a spinning governor raised pressure with road speed to push the shift valves. In the 5R55S, the PCM reads the speed sensors and drives these solenoids instead, so the pack is both the shift timer and the pressure control for every clutch and band apply. One weak variable force solenoid is enough to make a single shift flare while the others feel normal, which is why symptoms often look random.
The 5R55S also has two well-known mechanical faults that mimic a bad pack: worn servo pin bores in the case and worn variable force solenoid modulator bores in the valve body. Neither is fixed by a new pack.
Read the codes and freeze frame first. Unplug the case connector and look for transmission fluid wicking into the pins, since that alone causes intermittent solenoid codes. Watch commanded gear and solenoid current on a scan tool during a drive; a shift that flares while the commanded value is correct points to pressure, not wiring. Our 5R55S shift solenoid symptoms guide shows how to separate a pack fault from the servo pin bore wear that causes the classic 2-3 slip and P0735 on these units.
The pack fits transmissions with the 5R55S or 5R55W, which share the solenoid assembly. Common 5R55S vehicles are the 2005-2010 Mustang V6 and the 2003-2006 Lincoln LS and 2003-2005 Thunderbird; the W went in the 2002-up Explorer and Mountaineer. ATRA notes Ford used an early 1L2Z-7G391-AG pack on 2002-2003 units and the 2003 Lincoln, then a later 4L2Z-7G391-AA pack updated to 9L2Z-7G391-A from 2004 on, and the two are not interchangeable without care. Check the part number on your old pack and match the connector and shape to the photo, or send us your year and VIN before it ships. It does not fit the older 5R55E in Rangers. More parts for this family are on the 5R55 parts page.
If you would rather have a different pack option, compare the 9L2Z-7G391-AA solenoid block we also carry.
| Fits | 5R55S |
| Part type | Governor Pressure Solenoid |
| Condition | New Other (See Details) |
| 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. The 5R55S is fully electronic. Shift timing and line pressure come from the solenoid pack, controlled by the PCM using speed sensor inputs. Governor pressure solenoids are a Chrysler RE-series part.
No. It is a genuine OEM Ford pack removed from a running transmission and tested so each solenoid works correctly before shipment.
The W and S share the solenoid pack, but Ford changed part numbers over the years. Early 2002-2003 units used 1L2Z-7G391-AG and later units use 4L2Z-7G391-AA or 9L2Z-7G391-A. Match the number on your old pack or send us your VIN.
Often not. On the 5R55S that combination is very commonly caused by worn servo pin bores in the case. Diagnose the bores before replacing the pack.
There is no dipstick. Fill with Mercon V through the fill plug, using a fill adapter, then check level at the specified temperature with the engine running.
Yes. Clear the codes and reset the transmission adaptive values with a scan tool, then drive through all gears so the PCM relearns shift pressures.
