48RE Solenoid Kit

This 48RE solenoid kit is the governor side of the transmission in one piece: as the product photo shows, it is a governor body assembly with the governor pressure solenoid and pressure sensor mounted, plus a new gasket and four mounting bolts. It is aimed at 2003-2007 Ram 2500 and 3500 trucks with the 5.9L Cummins whose 48RE has started shuttle shifting at a steady speed, taking off in second or third, banging the 2-3, or setting P1762, P1763 or P1764. Because the solenoid, sensor and body arrive together, you replace the whole closed loop instead of guessing which half failed.

What the governor body does in a 48RE

The 48RE still makes its 1-2 and 2-3 shifts with hydraulic governor pressure working against throttle pressure. What is electronic is how that governor pressure gets made. The governor body bolts under the valve body transfer plate; the solenoid in it bleeds line pressure down to the governor pressure the PCM asks for, and the sensor reports back what actually came out. ATSG notes that the 3-4 shift is not influenced by governor pressure at all, so this assembly controls first through third only. The 48RE got a stronger overdrive section and heavier hard parts than the 47RE, but its shift timing still depends entirely on this small part.

Symptoms that point at the governor body

• Shuttle shifting between two gears at a steady cruise.
• Starting off in second or third, with the truck feeling gutless from a stop.
• Harsh or hanging 2-3 shift, or shift points that change as the fluid warms up.
• Codes P1762 (sensor offset), P1763 (sensor volts high) or P1764 (sensor volts low).
• Shifts that are fine on the highway but wrong around town, since the PCM sends full line pressure to the governor circuit above roughly 40 mph.

Not on this list: no fourth gear or no lockup. Those belong to the separate overdrive and TCC solenoids on the internal harness.

How to confirm it before ordering

Start with the output speed sensor, because GEARS points out the computer will not open the governor solenoid without that signal, which leaves the truck stuck in first. Then compare the scan tool governor pressure reading with a real 0-100 psi gauge on the governor tap; Jeff Parlee's Transmission Digest rule of thumb is about 1 psi per mph. ATSG's quick check is to unplug the case connector: governor pressure should jump to about 60 psi at idle in Drive. If it stays low, the problem is inside the governor body or its inlet screen. Our 48RE governor pressure solenoid guide has the complete test sequence, and the 48RE shift solenoid guide explains how to rule out the OD/TCC side.

Fitment

The listing names the 48RE without a year range, so treat fitment as something to check, not assume. The RE family used more than one governor pressure sensor design: Sonnax identifies an early oval-connector sensor on 1999-and-earlier units and a rectangular plastic sensor on 2000-later units, and ATSG says the sensor went through several design levels with different connectors. A 2003-2007 48RE uses the later style. Compare the connector and bolt pattern in the product photo with the governor body on your valve body, or send us your year and VIN and we will match it. Every RE-family part we carry is on the 48RE parts page; if you only need a solenoid, see the 1994-2007 pressure control solenoid and check its photo against your part, since RE parts counters often sell the governor pressure solenoid under that name.

Install notes

• Drop the pan and filter; the governor body sits under the transfer plate and comes off without pulling the valve body.
• Clean around it first. A debris-packed solenoid inlet screen is a common reason a governor reads high at a stop.
• Use the supplied gasket and bolts, and tighten evenly; a governor body that leaks pressure looks exactly like a weak solenoid.
• Inspect the internal harness pigtail to the sensor while you are in there and replace it if heat has cracked it; the internal wiring harness is listed separately.
• Refill with Mopar ATF+4. The 2006 Ram fluid capacity chart lists a 48RE service fill of about 3.8 liters (8 pints); check it hot in Neutral.
• Clear codes and road test. The PCM learns the sensor zero point by itself every time the truck comes to a stop.

Does this replace both the governor pressure solenoid and the sensor?

Yes. The photo shows the governor body with both the solenoid and the pressure sensor installed, plus a gasket and four bolts, so the closed loop is replaced as a unit.

Will it fix no fourth gear or no converter lockup?

No. On the 48RE the 3-4 shift and lockup are controlled by the separate overdrive and TCC solenoids on the internal harness, not by the governor body.

How do I know it matches my truck?

Match the governor pressure sensor connector and the body shape to what is on your valve body. Early RE units used an oval-connector sensor and later units a rectangular one. Send your year and VIN if you want us to confirm.

Can I change it without removing the transmission?

Yes. It mounts under the valve body transfer plate and is reached by dropping the pan and filter with the transmission in the truck.

What if the truck stays in first after I install it?

Check the output speed sensor signal. Without it the PCM will not open the governor solenoid and governor pressure stays at zero, which holds the truck in first.

• Dodge/RAM 48RE Governor Pressure Solenoid Failure: Symptoms and Fix
• 48RE Shift Solenoid Symptoms: Overdrive and TCC Solenoid Testing and Replacement
• 48RE Ram 3500 Cummins Shift Problems: Diagnosis and Fix
• 48RE Cummins Transmission Problems: Failure Points, Upgrades, and What Actually Breaks