5R55S Pressure Control Solenoid, new other (see details) and ready to install. Fits the 5R55S. Ships fast from the USA.
On a 5R55S there is no separate pressure control solenoid to buy. Ford built all three variable force pressure solenoids into one solenoid pack, together with the shift solenoids and the converter clutch solenoid. So when a 2005-2010 Mustang, a Lincoln LS or a later Explorer starts flaring into fourth, banging into gear or setting pressure control codes, the pack is the part that gets replaced. That is what this is: a genuine Ford 5R55W/5R55S solenoid pack carrying Ford numbers 9L2Z-7G391-AA and 4L2P-7G391-AA. It was removed from a running transmission, and every solenoid was function-tested before it was listed.
The pack holds eight solenoids: four on/off shift solenoids, one pulse width modulated TCC solenoid and three variable force solenoids known as PCA, PCB and PCC. The shift solenoids only line up the valves for each gear. The three variable force solenoids decide how quickly and how hard each clutch and band actually applies. They work the opposite way from what most people expect: as the PCM lowers the current to one of them, the pressure it produces goes up. During a Reverse engagement, for example, the PCM holds PCB at about half an amp to keep the reverse engagement control valve closed, then lowers PCC current so pressure builds and the direct clutch fills over roughly two seconds. A sticking or weak solenoid in this pack throws that timing off on every shift.
Sonnax points out that on high-mileage W and S units the VFS modulator valve bores in the valve body wear from constant cycling, especially in city driving, and the drop in clutch and servo pressure is often blamed on the solenoids when they are fine. Servo pin bore wear is the other common misdiagnosis. Before ordering, pull the pan and look at the fluid and debris, check the case connector for oil and bent pins, and watch commanded solenoid current against shift quality on a scan tool. If the bores are worn, a pack alone will not hold pressure. Our 5R55S shift solenoid symptoms guide and the 5R55S valve body symptoms guide walk through telling the two apart.
This pack fits the 5R55S and the 5R55W, which share the solenoid assembly. Sonnax identifies the S by its 38-tooth overdrive sun gear, where the W uses 24 teeth. Ford moved the Lincoln LS and Thunderbird from the 5R55N to the S for 2003, and the S also went into the 2005-2010 Mustang V6 and GT and into Explorers and Mountaineers from about 2004. The pack design depends on the year. According to ATRA, 2002-2003 units, including the 2003 Lincoln, used an early pack, 1L2Z-7G391-AG, while 2004-on units use the later design that Ford updated to 9L2Z-7G391-A, the number this pack carries. If you have a 2003 LS or Thunderbird, read the number on your old pack and send it with your VIN before ordering. It does not fit the 5R55N, which uses a reverse pressure switch this pack has no terminals for, or the separate-solenoid 5R55E. See the 5R55 parts page for the rest of this family.
| Fits | 5R55S |
| Part type | Pressure Control 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.
Not as a factory part. The PCA, PCB and PCC pressure solenoids are built into the solenoid pack with the shift and TCC solenoids, so the pack is the service replacement.
It is a genuine Ford pack that was removed from a running transmission and function-tested solenoid by solenoid. It is not a new-in-box part.
Yes for a 2005-2010 Mustang with the 5R55S. Those years use the later pack design, which Ford updated to the 9L2Z-7G391-A number this pack carries.
ATRA lists the 2003 Lincoln on the early 1L2Z-7G391-AG pack. Early and late packs deliver different pressures, so check the number on your old pack and send it with your VIN before ordering.
Only if pressure control is the cause. Worn VFS modulator bores in the valve body, burned clutches or servo pin bore wear all cause slipping that a pack cannot fix. Look at the fluid and pan debris first.
Mercon V, checked hot at the T30 Torx plug. The eight pack bolts take 71 lb-in (8 Nm) in sequence.
