Replaces the shift, EPC and TCC solenoids, internal harness, switches and filter on GM 4L60E and 4L65E units built 1993 through 2005.
A 1993-2005 Silverado, Tahoe, Sierra, S10 or Camaro that throws P0751 or P0756, slams into second, stays stuck in a gear or never locks the converter usually sends its owner looking for one solenoid. This kit is the whole electrical package inside the pan of a GM 4L60E or 4L65E: the 1-2 and 2-3 shift solenoids, the EPC pressure control solenoid, the TCC solenoid, the internal wiring harness, the pressure switch assembly, the filter and the pan gasket, so the electrical side is done in one pan drop.
The 4L60E has no shift linkage to the valves; the computer picks gears by switching two shift solenoids on and off. First gear is both on, second is the 1-2 solenoid off with the 2-3 on, third is both off, and fourth is the 1-2 on with the 2-3 off. If one solenoid sticks, the pattern breaks and the truck skips or holds a gear. The EPC solenoid is a variable-current valve that tells the pressure regulator how much line pressure to make, so when it wears the whole unit shifts too soft or too hard. The TCC solenoid applies the converter clutch for lockup on the highway. All of them hang off one internal harness that runs to the case connector, and that harness has been sitting in hot ATF for as long as the truck has been on the road.
Rule out the simple causes first. Sonnax notes that a battery dropping below 10.5 volts while cranking can set some or all of the 4L60E solenoid codes on start-up, so test the battery and cables before you drop the pan. Next, unplug the case connector by squeezing its tabs and pulling straight up, never prying, and measure through it: ATRA lists the 1-2 and 2-3 shift solenoids and the TCC solenoid at 20-40 ohms and the pressure control solenoid at 3.5-8 ohms. An open or shorted reading, or a reading that jumps when you wiggle the harness, points straight at this kit. A TCC slip code with good solenoid readings can be valve body bore wear instead, which no solenoid will fix. Our 4L60E high-mileage checklist walks through that split, and the 4L60E shift problems guide covers matching symptoms to the right part.
The kit is listed for GM 4L60E and 4L65E transmissions from 1993 through 2005, in trucks and cars such as the Silverado and Sierra 1500, Tahoe, Yukon, Suburban, S10, Sonoma, Blazer, Camaro, Firebird and Corvette. Cross-reference numbers on the kit are 10478112, 10478120, 24230298, 24215111, 24219581 and 24220158. GM changed the case connector, pass-through and solenoid styles during those years, so compare these numbers and the connector on your unit with the kit, or send us your year and VIN before ordering. All 4L60E parts are on the 4L60E parts page, and for 2003-and-up units you can compare this kit against the 6-piece master solenoid kit for 2003-up.
Drain and drop the pan, pull the filter, and note how the harness is routed and clipped before you touch it. Disconnect the case connector from outside, then unclip the harness inside and unbolt the solenoids from the valve body one at a time, so each new solenoid goes into the same bore it came out of. Lube each O-ring with clean ATF and seat it fully; a pinched O-ring leaks pressure and can bring the same symptom back. Torque the solenoid and pressure switch bolts lightly into the aluminum valve body. Route the new harness exactly like the old one, away from the manual valve linkage, and push the case connector in straight until it clicks. Install the new filter and gasket, refill with Dexron VI, clear codes and road test through every gear. If the shift feel was harsh before the codes started, a 4L60E shift kit can go in during the same pan drop. Read our filter and pan service guide for what the old filter and pan debris say about the rest of the unit.
| Fits | GM 4L60E / 4L65E, 1993-2005 |
| Includes | Shift solenoids, EPC, TCC, internal harness, pressure switch, filter, gaskets |
| Cross-reference | 10478112, 10478120, 24230298, 24215111, 24219581, 24220158 |
| Kit weight | 3.61 lb |
| Ships from | USA |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
The pan has to come down either way, and on a high-mileage 4L60E the harness insulation goes brittle in hot fluid. Replacing one solenoid and leaving an old harness is a common reason the same or a different code comes back weeks later.
Only if the TCC solenoid or its wiring is the cause. A TCC slip code with good solenoid resistance is often valve body bore wear or a converter problem, so measure the circuit first.
Check battery voltage while cranking first, then measure through the case connector. Typical readings are 20-40 ohms for the shift and TCC solenoids and 3.5-8 ohms for the pressure control solenoid. Wiggle the harness while you read to catch an intermittent wire.
The kit is listed for 1993-2005 4L60E and 4L65E units. For later trucks, match the part numbers and connector on your transmission, or send your year and VIN and we will confirm.
Clear the codes and road test through every gear. Many trucks adapt shift timing over the next few drives; if your vehicle supports a shift adapt reset with a scan tool, run it after the repair.
