Five new solenoids covering EPC, 1-2 and 2-3 shift, TCC PWM and 3-2 downshift for GM 4L60E, 4L65E and 4L70E units built 2003 and later.
This is the set for a late GM 4L60E, 4L65E or 4L70E, built 2003 and on, that is throwing solenoid codes or shifting like it has a mind of its own. It is five new solenoids, not cleaned or retested cores: the EPC pressure control solenoid, the 1-2 and 2-3 shift solenoids, the TCC PWM lockup solenoid and the 3-2 downshift solenoid. Buyers usually land here with a Silverado, Sierra, Tahoe, Yukon or Suburban that is stuck in one gear, flares then bangs, or will not lock the converter at cruise.
Think of the 4L60E valve body as a hydraulic computer that the PCM steers with these five parts. ATRA's solenoid chart classes it as a two-solenoid unit: the 1-2 (A) and 2-3 (B) solenoids are both on in first, B alone in second, both off in third and A alone in fourth. Lose one of them and the gear pattern collapses. That is why a dead A or B solenoid typically leaves the truck in a single gear.
The other three trim the shifts. The EPC solenoid varies line pressure with throttle, so a worn one gives flare-up shifts one minute and harsh ones the next. The TCC PWM solenoid ramps the converter clutch on rather than slamming it. The 3-2 solenoid manages the band apply when you kick down from third. Sonnax notes that every one of them is fed by AFL oil regulated to roughly 115 psi, so a low or dirty AFL supply can make healthy solenoids look bad.
Solenoid codes on this transmission are usually electrical or a sticking valve, but not always the solenoid itself. ATRA traced a whole group of codes, P0740, P0753, P0758, P0785 and P1860, to one poorly crimped terminal on a shared feed circuit. Unplug the case connector and look for oil wicked into it or pushed-back pins before you replace anything. Transmission Digest also published a 1993 C1500 that kept starting in second after new solenoids and even a new valve body, because the real fault was elsewhere in the hydraulics. If the electrical side checks good and the complaint stays, look at the bores. Our guides on shift solenoid codes P0753 and P0758 and the 3-2 downshift solenoid and P0785 cover the test steps.
For GM 4L60E, 4L65E and 4L70E transmissions from 2003 and later. GM changed the shift solenoid terminal style partway through the run, so early 1993-2002 parts will not plug into a late valve body, and these will not plug into an early one. Match the connector bodies on your valve body to the photos before ordering, or send your year and VIN for a check. Note that this kit does not include the pressure switch manifold; if your codes include a range or TFP fault, the 2003-up kit with pressure switch is the better buy. Everything else for this unit is on our 4L60E parts page.
The labor here is the pan drop, not the solenoids, which is the argument for doing all five together. Drain and drop the pan, remove the filter, unplug each solenoid at the internal harness and pull the retainers. Fit each new solenoid with its O-ring wet with ATF and pressed square in the bore; never reuse the old O-rings. Install a new filter and pan gasket, tighten the pan bolts in a crossing pattern, refill with Dexron VI and set the level hot in park with the engine running. Clear codes and reset adaptives so the PCM relearns line pressure.
If the truck also had a soft or late 1-2 shift, this is a good time to add a 4L60E shift kit, and a worn range switch is worth checking while you are under there if the truck sometimes will not crank in park.
| Fits | GM 4L60E / 4L65E / 4L70E, 2003 and later |
| Pieces | 5 |
| Includes | EPC pressure control, 1-2 shift, 2-3 shift, TCC PWM, 3-2 downshift |
| Condition | All new parts |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
All five are new parts, not cleaned or retested cores.
No. It is the five solenoids only. If you have range or TFP codes such as P1810, choose our 2003-up kit that includes the pressure switch.
No. The 2002 and earlier 4L60E uses different solenoid connectors. This kit is for 2003 and later 4L60E, 4L65E and 4L70E units. Send your year and VIN if you are unsure.
They sit in the same fluid and have the same miles. The work is dropping the pan, so replacing the set once avoids a second teardown when the next original solenoid fails.
Refill with Dexron VI, set the level hot, clear codes and reset the transmission adaptive values with a scan tool, then road test through every gear and confirm converter lockup.
