Replaces every solenoid, the pressure switch and the internal harness on 2003-2005 GM 4L60E and 4L65E valve bodies, with a new filter and pan gasket.
A 2003, 2004 or 2005 GM truck, van or SUV with the 4L60E or 4L65E (RPO M30 or M32) that starts in second, will not find third, never locks the converter, or shifts like it was rear-ended usually has something wrong on the electrical side of the valve body. This ten-piece kit is for owners who want to rule that whole side out in one service instead of chasing parts one at a time. It contains shift solenoid A (1-2/3-4), shift solenoid B (2-3), the 3-2 downshift solenoid, the EPC pressure control solenoid, the TCC PWM solenoid, the TCC on/off solenoid, the pressure manifold (TFP) switch, the internal wiring harness, a filter and a pan gasket. The listing cross-references GM 24230298, 24215111, 24209121, 24208576, 24227747, 24227792, 24212327, 8677314 and 8683187.
These are the last three years of the electrical design GM ran from 1996 through 2005; for 2006 the transmission gained an internal input speed sensor and a revised harness, which is why this kit stops at 2005. In this layout the computer cannot see input shaft speed directly. It infers what the transmission is doing from the pressure manifold switch, which reports which hydraulic circuits are pressurized, and that makes the TFP switch more important on these trucks than many owners realize. A leaking or stuck switch can tell the computer the selector is in the wrong range, and the result looks like a shift solenoid fault. The two shift solenoids pick the gear, the EPC solenoid sets line pressure for every shift, the TCC on/off and PWM solenoids handle converter lockup and its apply rate, and the 3-2 solenoid times part-throttle downshifts.
Multiple solenoid codes at the same time are a warning, not a parts list. ATRA traced that pattern on these units to the shared solenoid power feed that runs through the ignition switch and a fuse to the transmission connector, so measure that feed against battery voltage first. Then read each solenoid at the case connector and look at the pressure switch status on a scan tool while moving the selector through every range. Transmission Digest published a case where a solenoid read in spec on the meter and still responded too slowly to shift on time, which is one more reason a full set makes sense on a high-mileage unit. Our P0748 pressure control solenoid guide covers the EPC circuit and the 4L60E common problems guide helps you separate electrical faults from worn clutches and the sun shell.
Listed fitment is GM 4L60E and 4L65E, 2003-2005, in rear-wheel-drive and four-wheel-drive GM trucks and SUVs such as the Silverado 1500, Sierra 1500, Tahoe, Suburban and Yukon. GM changed harness and connector details on this transmission more than once, so do not cross this kit onto a 2006-up unit with an input speed sensor, and if your truck was fitted with a replacement transmission from another year, match the old harness, solenoid plugs and switch to the new parts before installing. Send us your year and VIN if you want a fitment check. Everything we stock for this unit is on the 4L60E parts page.
Drain the fluid and drop the pan, then pull the old filter straight down so the seal comes out with it rather than staying in the pump bore. Unplug the harness, remove the pressure switch and the solenoid clips and bolts, and swap each solenoid for its matching new piece, wetting each O-ring with Dexron VI. Torque the pressure switch bolts evenly so the gasket seals; an uneven switch is a common source of a new leak and a false range reading. Seat the new filter fully, fit the pan gasket dry, run the pan bolts down in a cross pattern and refill with Dexron VI. Clear codes, reset adapts and relearn over several drive cycles. If the old filter was packed with friction material, plan for a rebuild such as the 2004-2010 master rebuild kit; if the circuits test good and shifts are still wrong, a 2003-2005 refurbished valve body addresses bore wear the solenoids cannot.
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Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
It is listed for 2003-2005. For 2006 GM added an input speed sensor and revised the harness, so a 2006-up unit needs the matching later kit. Send us your VIN if you are unsure what year your transmission is.
It is the TFP switch that bolts to the valve body and tells the computer which range circuits have pressure. On 2003-2005 units the computer relies on it heavily, and a leaking or failed switch can cause shift complaints that look like solenoid faults.
The filter and pan gasket are included. You will need fresh Dexron VI to refill after the pan drop, plus a scan tool to clear codes and reset adapts if available.
Only if the cause is electrical. A stripped sun shell or burned 3-4 clutch pack also takes out 3rd and 4th on this transmission, so check the fluid and the solenoid circuits before buying.
Replace them one at a time, matching each new part to the old one by shape and connector. The 3-2, TCC PWM and EPC solenoids each have their own mounting location and are not interchangeable.
