45RFE Solenoid Kit, new and ready to install. Fits the 45RFE. Ships fast from the USA.
A 45RFE that loses reverse, drops into a single gear after a cold start, or lights the dash with a solenoid or low-voltage code is a common story on Dodge Ram 1500, Dakota and Durango trucks and on Jeep Grand Cherokee and Liberty models that used this four-speed. Most of those faults live in one part: the solenoid pack that sits on the valve body under the pan. This is a new Mopar 45RFE solenoid pack kit. The listing photo also shows a pan filter, the cylindrical cooler return filter and a pan gasket, so check the photo to see exactly what arrives.
Chrysler designed the 45RFE so the computer, not a governor or throttle cable, decides every shift. The pack holds the clutch solenoids, the pressure control solenoid and the pressure switches the computer reads back. The most important one to understand is the multi-select solenoid. According to the ATSG write-up in Transmission Digest it is energized in every range except reverse, 3rd and 4th, and because it applies pressure when it is switched off, the manual valve uses its output to apply the low/reverse clutch in reverse. That same solenoid feeds the solenoid switch valve, which Chrysler's service information describes as routing low/reverse solenoid oil to the low/reverse clutch in 1st and to the converter clutch in 2nd through 4th. When that valve or the solenoids feeding it misbehave, you get the 45RFE's best-known complaint: no drive after shifting out of reverse.
Start electrical. Every solenoid in the pack shares one supply feed through the transmission control relay, so a single shorted coil can take the voltage down and set codes for solenoids that are actually fine. GEARS lists roughly 1.8 ohms per shift solenoid and 3.7 ohms for the pressure control solenoid when measured at the case connector; Sonnax publishes nominal values of 1.3 and 3.5 ohms. A coil far outside those numbers, or open, condemns the pack. Our 45RFE shift solenoid symptoms and testing guide covers the full test sequence, and the 45RFE and 545RFE problems overview explains which faults are pack faults and which are worn clutches.
The listing covers the 45RFE without a specific year range. That matters, because the pack was revised during the run and Sonnax notes the 2010 and later version dropped the overdrive solenoid. Before ordering, compare the connector and part number on your old pack with the product photo or send us your year and VIN so we can check it. If you already know your model year, the dated 2004-2009 45RFE solenoid kit and the 2002-2012 version are listed separately, and the full range of parts is on the 45RFE / 545RFE collection page.
If the fluid was burnt or full of friction material, plan for a 45RFE overhaul kit instead of a pack alone.
| Fits | 45RFE |
| Part type | Solenoid Kit |
| Condition | New |
| Brand | Mopar |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
That is the classic solenoid switch valve fault. The valve redirects low/reverse solenoid oil between the low/reverse clutch and the converter clutch, and if it latches in the wrong position the computer sets P1775 or P1776 and drive is lost. A failing pack is one cause; a sticking valve in the valve body is the other, so test the solenoids before buying.
The 45RFE and 545RFE share the same pack design, but this listing is for the 45RFE and the pack changed over the years. Match your connector and part number, or send us your year and VIN to confirm.
It means the computer saw low supply voltage to the solenoids. A weak battery or a bad transmission control relay can cause it, but a shorted solenoid inside the pack can drag the supply down too, which is why the pack is tested by resistance before replacement.
ATF+4. Refill after the pan is back on, start the engine and check the level hot.
Yes. Run the Quick Learn with a scan tool after installing a new pack, then drive the truck until the fluid is fully warm so the adaptive shift values can settle.
