4L80E Solenoid Kit 2003, remanufactured and ready to install. Fits the 4L80E. Ships fast from the USA.
When a 2003 HD Silverado or Sierra, Suburban 2500, Express or Savana starts shifting erratically, falls into second-gear limp mode, or logs shift solenoid A or B performance codes, the solenoid set is the obvious suspect. This listing is named a solenoid kit, yet the photo shows the solenoids already installed on a complete remanufactured 4L80E valve body. That matters: Sonnax notes that repeated solenoid codes on this unit often trace to low solenoid feed pressure from worn valve body bores, so a loose kit dropped onto a tired body can bring the same code right back. Here you replace both at once. If you only want the loose solenoids, contact us and we will steer you to a 1991-2003 kit.
The solenoid set covered by our 1991-2003 kits is four pieces: shift solenoids A and B, the pressure control (EPC) solenoid and the TCC solenoid. A and B are simple on/off valves; the computer switches them in combinations to stroke the shift valves and select first through fourth. The EPC solenoid is current-controlled and sets line pressure for throttle and load. The TCC solenoid applies converter lockup. All of them run on oil regulated by the actuator feed limit valve, so the bore that valve rides in is as important to shift quality as the coils themselves. From 2004 the internal harness and solenoid set were revised, which puts 2003 right at the changeover.
Measure resistance at the case pass-through connector before pulling the pan. Shift solenoids read 18 to 24 ohms and the TCC solenoid 10 to 14; a single shared ignition feed powers both shift solenoids and the TCC solenoid, so a fault there can set several codes together. The full pinout and test sequence is in our 4L80E shift solenoid symptoms guide. For a hard-shift complaint, our EPC solenoid guide explains how to separate an electrical default from a worn valve body using a line pressure test.
This listing is titled for the 2003 4L80E, and the assembly is described as an updated 2003-and-up valve body with the solenoids included. Because loose solenoid kits split at 2003 and 2004, the safest check is your hardware, not the calendar. Check the casting number and the solenoid connectors on your old valve body against the photo, or send us year and VIN for a confirmation. Every other 2003 part is in the 4L80E collection, and if the bores are fine and you only need coils, the 4-piece EPC, shift and TCC kit for 1991-2003 is the lighter repair.
Drain and drop the pan, remove the filter, unplug each solenoid and the pressure switch connections, and unhook the manual valve link before lowering the body. Keep track of any checkballs. Tighten the new body evenly to spec in a pattern. Look closely at the case pass-through connector: Sonnax documents broken retention tabs that let it push into the pan area, so fix that before the pan goes back on. Install a fresh filter and gasket kit, fill with Dexron VI, clear codes and let the computer re-adapt over a normal drive cycle.
| Fits | 4L80E 2003 |
| Part type | Solenoid Kit |
| Condition | Remanufactured |
| 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.
The photo shows them mounted on a complete remanufactured 4L80E valve body. If you only want loose solenoids, contact us before ordering and we will suggest a 1991-2003 kit.
Shift solenoids A and B, the pressure control (EPC) solenoid and the TCC solenoid. 2003 sits at the changeover to the 2004-up harness and solenoid set, so match the connectors on your old unit or send us the VIN.
On the 4L80E, worn valve body bores, especially the actuator feed limit valve, lower solenoid feed pressure. New solenoids on a worn body can still set codes, which is why a complete valve body is often the lasting fix.
At the case connector, shift solenoids should read 18 to 24 ohms and the TCC solenoid 10 to 14 ohms. Check the shared ignition feed before condemning several parts at once.
A new filter and pan gasket, and Dexron VI ATF, which is back-serviceable for the original Dexron III. Clear codes and drive a full cycle afterward.
