4L80E Solenoid Kit 2004, new and ready to install. Fits the 4L80E. Ships fast from the USA.
This kit is for owners of a 2004 truck or van with the 4L80E: Silverado and Sierra 2500HD and 3500, Suburban 2500, Yukon XL 2500, and the Express and Savana heavy vans. If yours is starting in second, holding one gear, hitting every shift hard, or showing a shift solenoid, EPC or converter clutch code, these are the parts that usually need replacing. The photo shows the internal harness with its round case connector and pressure switch manifold, shift solenoids A and B, the EPC pressure control solenoid and the TCC solenoid. A filter and pan gasket are not shown, so plan to buy them separately.
Gear selection in the 4L80E is purely electrical. Two on/off solenoids, A and B, route fluid to the shift valves, and the pattern of which one is on decides first through fourth. The EPC solenoid is a variable force unit that turns a commanded current into line pressure, so it sets how hard each clutch pack and the band apply. The TCC solenoid handles converter lockup. The pressure switch manifold on the valve body reports the range the driver selected back to the computer. By 2004 these trucks were well into the OBD-II era, so faults come in as P-codes rather than the flash codes of the early units.
Pull the codes and note whether each is a circuit or a performance code. Circuit faults are checked with a meter: GM charts list roughly 19 to 31 ohms for this family of on/off shift solenoids, so a reading far outside that, or an open, condemns the part or the harness. Performance codes need more thought. Sonnax ties repeat solenoid B codes and low solenoid feed pressure to wear in the valve body, which no solenoid kit will fix. The Silverado 2500 shift problems guide lays out the order of checks, and the EPC solenoid symptoms guide covers the line pressure test.
2004 sits right on the line where GM revised the 4L80E electrically. Sonnax groups its valve bodies as '97-'03 and '04-later, and sells an adapter harness for running an early-style ('92-'02) EPC solenoid in a late-style ('03-later) unit, which tells you the EPC plug changed. Because a 2004 transmission could be built on either side of a running change, do not order on the year alone. Compare the EPC connector, the case connector and the pressure switch manifold in the photo with the parts in your pan, or send us the year and VIN and we will match it for you. If your unit is the later style, the 2004-up solenoid kit with harness and filter may be the closer match. The full range of parts is on the 4L80E collection page.
With the truck level, drain the fluid, remove the pan and pull the filter with its neck seal. Disconnect the harness at the pass-through and at each solenoid, unbolt the pressure switch manifold, then remove the shift, EPC and TCC solenoids. Tighten the new manifold's bolts evenly in steps so it seals flat; an uneven manifold can leak and feed the computer a false range. Lube each O-ring with ATF before seating its solenoid, and clip the harness on the original path. Fit a new filter and gasket, refill with Dexron VI, and set the level at operating temperature. Clear codes and road test through all gears and lockup.
If you only have a shift solenoid code and the harness looks healthy, the A and B shift solenoid pair is the budget fix. Units that are coming apart anyway can take the 4L80E overhaul gasket and seal kit at the same time.
| Fits | 4L80E 2004 |
| Part type | Solenoid Kit |
| Condition | New |
| Brand | GM |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
It is listed for 2004 4L80E units. Because 2004 falls on a running change, compare the EPC plug, case connector and pressure switch manifold with the photo, or send us the VIN and we will confirm.
The photo shows the internal harness with case connector and pressure switch manifold, shift solenoids A and B, the EPC pressure control solenoid and the TCC solenoid. A filter and pan gasket are not shown.
Measure across its terminals. GM diagnostic charts put this family of on/off shift solenoids at roughly 19 to 31 ohms. Check through the case connector first, then at the solenoid, to tell a bad solenoid from a bad harness.
Dexron VI. These trucks were filled with Dexron III from the factory, and Dexron VI is approved as its replacement. Set the level hot with the engine running.
Not always. Repeat solenoid B codes and low solenoid feed pressure are often caused by worn valve body bores. If the code returns with good solenoids and a good harness, look at the valve body.
