4L70E Tcc Solenoid 2003, new and ready to install. Fits the 4L70E. Ships fast from the USA.
If a 2003 Silverado, Sierra, Tahoe, Yukon, Suburban or Avalanche has developed a converter shudder at 40 to 60 mph, a lockup that will not hold, or slip codes such as P1870, this listing covers the solenoids that control it. As pictured, it is a set of five: the TCC PWM solenoid that meters converter apply, plus the 1-2 and 2-3 shift solenoids, the pressure control solenoid and the 3-2 control solenoid. Replacing them as a set makes sense on a high-mileage unit, because they all sit on the same valve body and share the same fluid.
By 2003 this family was using EC3 control, which Sonnax dates to 1998. Instead of slamming the converter clutch on, the computer pulses the TCC PWM solenoid to ramp apply pressure up gradually and often holds the clutch at a controlled 20 to 40 RPM of slip. The solenoid is fed by the actuator feed limit circuit, roughly 115 psi in this family according to Sonnax, so a weak feed shows up as poor lockup even with a good solenoid. A worn solenoid that cannot hold a steady duty cycle produces the classic shudder and the slip codes that follow.
Watch TCC duty cycle and slip together on a scan tool. If duty cycle rises but slip does not fall, the problem may be hydraulic. Sonnax documents that constant EC3 oscillation wears the TCC regulator and isolator bores in the aluminum valve body, letting apply pressure exhaust, and that wear sets the same 894 and 1870 codes as a bad solenoid. A vacuum test of those bores tells you whether a solenoid set alone will cure it. Transmission Digest adds that once slip codes push line pressure high, the 1-2 shift goes harsh, so fix lockup before chasing shift feel. Our valve body testing guide walks through the bore checks, and the pressure control solenoid guide shows how to read the EPC side of the set.
A 2003 transmission carries a 4L60E or 4L65E tag; GM applied the 4L70E name later, and we list the family under that name. 2003 matters because it is the first year of the late-style pressure control solenoid, which Sonnax notes uses a different pin and connector layout from the 1992-2002 design. A 2002 or earlier unit will not accept the late solenoid without an adapter, so do not order this set for a 2002 truck. Match the connectors in the photo with your old solenoids, or send us your year and VIN. The interchange guide covers what crosses over, and the full parts list is on the 4L70E collection page.
If shift quality is also a complaint, a 2003 shift kit goes in on the same pan-down job.
| Fits | 4L70E 2003 |
| Part type | Tcc Solenoid |
| Condition | New |
| 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.
As pictured, five solenoids: TCC PWM, 1-2 and 2-3 shift solenoids, pressure control and 3-2 control. If you need the contents confirmed before ordering, message us.
Not without changes. 2002 and earlier units use the early-style pressure control solenoid with a different connector and pin layout. This set is for 2003, the first year of the late style.
Only if the solenoid is the cause. Worn TCC regulator and isolator bores set the same code, so vacuum test the valve body or plan to repair the bores at the same time.
Dexron VI, which GM supplies in place of the Dexron III these trucks were originally filled with. Check the level hot.
Clear the codes and drive normally. The computer adapts shift timing over several drive cycles, so judge lockup and shift feel after a few days of driving.
