4R70W Pressure Control Solenoid 1998-2004, new and ready to install. Fits the 4R70W. Ships fast from the USA.
This is a new electronic pressure control (EPC) solenoid for the 1998-2004 Ford 4R70W, the four-speed automatic behind the V8 in the F-150, Expedition and Navigator, the Mustang, and the Crown Victoria, Grand Marquis and Town Car. Owners usually find it while chasing one of two opposite complaints: a truck that slides through the 1-2 and 2-3 when it is pulling, or one that suddenly slams into Drive and shifts hard everywhere with P1746 or P1747 stored. Both trace back to line pressure, and this solenoid is what sets it.
There is no throttle cable on this transmission. The PCM looks at throttle angle, engine load, gear and fluid temperature, then sends a varying current to the EPC solenoid mounted in the case. The solenoid turns that current into a small signal pressure, EPC oil, that pushes on the spring end of the pressure regulator valve. More EPC oil, more line pressure, and firmer clutch and band apply.
Ford built the circuit backwards on purpose. Ford's patent on this control system describes a variable force solenoid that turns a 0-1 amp signal into 0-6 bar of output, with maximum pressure at zero current. That is why a solenoid with a broken coil or an unplugged connector gives you harsh shifts instead of no movement: the truck defaults to full pressure so it can still be driven.
Start at the case connector. Sonnax's testing booklet for this family lists the EPC solenoid at 2-5 ohms, measured across pins 7 and 10 on the 10-pin case connector or pins 4 and 6 on the 8-pin version. A short sets P1747, an open sets P1746. If the coil reads in range but the code keeps returning, inspect the vehicle harness and the connector terminals before dropping the pan.
A good ohm reading does not prove the solenoid regulates, so put a gauge on the line tap and test cold and hot. Pressure that rises fine cold and fades once the fluid is hot points to wear in the pressure regulator bore, not the solenoid. Transmission Digest's "I Lost My EPC!" describes blowing air into the TV pressure port: air out of the filter opening means EPC oil is being siphoned back to the pump, and a new solenoid will not cure it. Our 4R70W EPC solenoid symptoms guide lays out every step, and the Expedition shift problems guide shows how this fault feels in the heavier trucks.
Listed for 1998-2004 4R70W transmissions. Sonnax splits this family's case connectors into three generations, 1997 and earlier, 1998-2008, and 2009 and later, and the EPC solenoid changed at the 1998 break. Catalogs commonly cross-reference this later solenoid to Ford service number F8AZ-7G383-AB. If your old solenoid has an adjusting screw and lock nut on the end, your transmission is an earlier unit and needs the 1992-1997 4R70W EPC solenoid instead. Build dates and model years do not always match, so compare the connector and snout on your old part, or send us your year and VIN and we will check it. Everything else for the job is on the 4R70W parts collection.
Drain and drop the pan and pull the filter. The EPC solenoid sits in the case near the manual shaft, held by a bracket and a single 8 mm bolt. Lube the new O-rings with ATF and push the snout in straight; a rolled O-ring leaks EPC oil and gives you high pressure in Park. Torque the bracket bolt, refit the filter and pan, and fill with MERCON V, the fluid Ford's Motorcraft chart specifies for the 4R70W, without additives.
Clear codes, reset adaptive memory with your scan tool, and confirm line pressure with a gauge before the customer drives away. Since the pan is already off, a deep aluminum pan with a drain plug makes every later fluid change a clean drain instead of a messy pan drop, and a truck that tows should have a working auxiliary transmission cooler so heat does not cook the new part.
| Fits | 4R70W 1998-2004 |
| Part type | Pressure Control Solenoid |
| 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.
Probably not. The 1997 and earlier 4R70W uses the adjustable early solenoid with a screw and lock nut on the end. This part is the 1998-2004 design. If your old solenoid has an adjuster, order the 1992-1997 version, or send your VIN and we will confirm.
Sonnax lists 2-5 ohms for the EPC solenoid on this family, measured at pins 7 and 10 of the 10-pin case connector or pins 4 and 6 of the 8-pin connector. Near zero is a shorted coil, an open reading is a broken one.
On the 4R70W, zero current to the EPC solenoid means maximum line pressure. When the circuit opens, the PCM loses control and the transmission defaults to full pressure, so every shift and engagement feels harsh until the circuit is repaired.
Only if the solenoid is the cause. Slipping that appears only after the fluid is fully hot usually means a worn pressure regulator bore is leaking EPC oil away. Gauge line pressure cold and hot and do the compressed air test before buying.
MERCON V. Ford's Motorcraft fluid chart lists MERCON V for the 4R70W and 4R75W and warns against supplemental additives.
Clear the codes and reset the transmission adaptive values with a scan tool, then drive the truck through several full shift cycles. Verify line pressure with a gauge so you know the new solenoid is following the PCM command.
