Five-solenoid set for the GM 4L60E and 4L65E: shift A and B, 3-2 downshift, EPC pressure control and TCC PWM, listed for 1993-2006 units.
A Silverado, Sierra, Tahoe, Yukon, Suburban, S-10, Blazer or Camaro with a 4L60E that suddenly sits in second gear, bangs into drive, or refuses to lock the converter on the highway is usually telling you something on the valve body has lost its electrical edge. This refurbished five-piece set covers the solenoids behind those complaints: shift solenoid A, shift solenoid B, the 3-2 downshift control solenoid, the EPC pressure control solenoid and the TCC PWM converter clutch solenoid. It is listed for 1993-2006 GM units, including the 4L65E and 4L70E, and because the parts are reconditioned rather than new, the full set costs far less than a new OE kit.
The PCM runs the 4L60E entirely by switching current to these parts. Shift solenoids A and B are the gear selectors. GEARS Magazine classes the 4L60E as a two-solenoid Type 1 unit, so the PCM picks a gear by the on/off pattern of the pair: on/on is first, off/on is second, off/off is third and on/off is fourth. That pattern is useful when you diagnose, because a solenoid stuck open or closed produces a predictable wrong gear. The EPC solenoid is different: it is fed a varying current to raise or lower line pressure, so a worn one shows up as shift quality problems rather than wrong gears. The TCC PWM solenoid is pulsed to ramp the converter clutch on smoothly, and the 3-2 solenoid controls how quickly third releases on a part-throttle or kickdown downshift.
First, look at the fluid. If it is black or the pan holds heavy friction material, the problem is mechanical and a solenoid set will not fix it. With clean fluid, use the gear pattern above: a scan tool that shows which gear is commanded versus the gear the truck is actually in tells you whether solenoid A or B is failing to respond. Then check the circuit itself. ATRA notes that the solenoid power feed arrives at case connector terminal E, so confirm battery voltage there with the key on before condemning parts. If one solenoid tests bad electrically but the others pass, the hydraulics may still be at fault; Sonnax recommends vacuum testing 4L60E valve body bores, since bore wear in this family causes the same TCC and shift complaints. Our shift solenoid A and B code guide and the P0748 pressure control solenoid guide go through each test step by step.
The listing names GM vehicles with the 4L60E, 4L65E and 4L70E from 1993 through 2006. Within that span GM changed the TCC and pressure switch arrangement, and this set includes only the five solenoids above, with no internal harness, separate TCC on/off solenoid or pressure switch manifold. Before ordering, pull the pan or compare a photo of your valve body against the product images, and match the connector shape on each solenoid. If you are not sure which version you have, send us your year and VIN and we will confirm it. You can see every solenoid and harness option for your unit in the 4L60E parts collection.
With the pan drained and dropped and the filter out, unplug the harness from each solenoid. Shift solenoids A and B are held by retaining clips and slide out of their bores; the EPC, 3-2 and TCC PWM solenoids are bolted to the valve body. Coat each new O-ring with clean ATF before pushing the solenoid home so the seal does not tear, then torque the bolts to spec and reconnect every plug firmly. Since the harness is not part of this set, inspect it closely for brittle insulation, cracked connector locks and loose terminals; if it is tired, the solenoid kit with harness, filter and gasket is the better buy. Install a new filter and pan gasket, refill with fresh Dexron VI ATF, set the level hot, clear codes and road test through every gear with converter lockup.
| Transmission | GM 4L60E, 4L65E, 4L70E (listed 1993-2006) |
| Pieces | 5 |
| Includes | Shift solenoid A, shift solenoid B, 3-2 downshift solenoid, EPC solenoid, TCC PWM solenoid |
| Condition | Refurbished |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Five: shift solenoid A (1-2/3-4), shift solenoid B (2-3), the 3-2 downshift control solenoid, the EPC pressure control solenoid and the TCC PWM solenoid. There is no harness or pressure switch manifold in the set.
No, they are refurbished. That is why a full five-piece set costs well under the price of a new OE master kit.
It is listed for 1993-2006, but GM changed the TCC and pressure switch layout over those years. Match the connectors and mounting on your old solenoids to the photos, or send us your year and VIN to confirm.
Not strictly, but if the pan is already down on a high-mileage unit, replacing the full set means the other solenoids of the same age are not the next pan drop. Check the power feed and harness first so you are not replacing parts for a wiring fault.
A new pan filter and gasket every time, fresh Dexron VI fluid, and the internal harness if its insulation is cracked or its connector locks are broken.
