4R70W Pressure Control Solenoid, new and ready to install. Fits the 4R70W. Ships fast from the USA.
If you are holding an old solenoid or a parts list with the number D76431B on it, this is the matching new 4R70W electronic pressure control (EPC) solenoid. It is the part shops reach for when an F-150, Expedition, Navigator, Mustang or Town Car comes in with P1746 or P1747 on the scan tool, hard shifts in every gear, or a slow, slipping shift under load. The B suffix matters: it separates this later-style solenoid from the plain D76431 used on early transmissions, and the two are not interchangeable.
This transmission has no throttle valve cable, so the PCM is the only thing deciding how hard the clutches and bands clamp. It does that through the EPC solenoid, a variable force solenoid that sits in the case and meters a signal oil to the pressure regulator valve. Low current from the PCM gives high line pressure and high current gives low pressure. When the EPC solenoid stops responding, the whole transmission loses its sense of how much pressure each shift needs.
An EPC code is a circuit code, not a verdict on the solenoid. ATRA's Gears Magazine makes this point in its article on solenoid circuit testing: the code covers the power feed, the ground, the wiring, the connectors and the PCM, and the solenoid is only one link. Gears also warns against using a test light on these circuits. Use a digital meter, and work from the PCM side toward the transmission.
At the case connector, Sonnax gives 2-5 ohms for the EPC solenoid on this family. If the solenoid reads right there but the code keeps coming back, the fault is upstream. Transmission Digest describes a 4R70W that came out of an overhaul starting in a higher gear with solenoid codes that were not there before. The cause was a poor-quality aftermarket case connector with two terminals pushed back into the shell. Inspect every pin before you condemn a new solenoid. Once the electrical side is proven, gauge line pressure; our 4R70W EPC solenoid guide covers the gauge and air tests, and the shift solenoid testing guide walks through the case connector checks.
This listing does not name model years, so the reference number is your guide. D76431B is the number catalogs use for the 1998-2004 AODE, 4R70W and 4R75 EPC solenoid. If your old solenoid carries the D76431 number with no suffix, or has an adjusting screw and lock nut on its end, you have an early transmission and need the 1992-1997 4R70W EPC solenoid. Sonnax treats 2009 and later units as a separate case connector generation, so do not assume a late 4R75W takes this part; the 4R75W EPC solenoid listing covers that unit. For a 2005-2008 transmission, or any time you are unsure, send us the year and VIN and we will match it. The 4R70W collection has the rest of the family's parts.
Remove the pan and filter, unplug the solenoid, take out its bracket bolt and pull it straight out of the case. Set the old part next to the new one and confirm the number, connector and snout match. Wet the O-rings with ATF, seat the solenoid without twisting it, and reinstall the bracket. Ohm the EPC circuit again through the case connector before the pan goes back on, so you know the connection is good while it is still easy to fix.
Refill with MERCON V, clear codes and reset adaptive memory. If the line pressure test turns up worn bores, a replacement 4R70W valve body is the faster fix than chasing leaks one valve at a time, and a converter that will not lock up is often cured with a new TCC solenoid during the same pan drop.
| Fits | 4R70W |
| Part type | Pressure Control Solenoid |
| Condition | New |
| Brand | OEM |
| Reference | D76431B |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
D76431 is the early, adjustable EPC solenoid used on 1992-1997 transmissions. D76431B is the later 1998-2004 style without the adjuster. Match the number on your old part, or check whether it has an adjusting screw and lock nut.
The code covers the whole circuit, not just the solenoid. Check the vehicle harness, the case connector terminals and the internal harness with a digital meter. Transmission Digest documented a case where pushed-back terminals in an aftermarket case connector set solenoid codes after an overhaul.
Unplug the transmission case connector and measure across the EPC terminals. Sonnax lists 2-5 ohms for this family. A reading in range proves the coil, but a line pressure gauge is still needed to prove the solenoid regulates correctly.
Do not assume it does. Sonnax treats 2009 and later units as a separate case connector generation. Send us your year and VIN, or see the 4R75W EPC solenoid listing.
MERCON V, the fluid Ford specifies for the 4R70W and 4R75W. Check the level hot after the first drive.
