4L60E Refurbished Master Solenoid Kit with Harness, 2003-Up

This is a refurbished 4L60E internal solenoid and harness assembly as pictured: the internal wiring harness with the pass-through connector, the manifold pressure switch plate, the A and B (1-2 and 2-3) shift solenoids, the 3-2 downshift solenoid, the EPC pressure control solenoid, the TCC solenoid and the PWM solenoid. It is listed for GM trucks, vans and SUVs with the 4L60E from 2003 on, and the same unit family covers the 4L65E and 4L70E.

Swap the whole assembly when you are chasing multiple codes at once or a harness that has been cooked by heat: P0751/P0756 shift solenoid performance, P0748 or P1870-type pressure and TCC slip complaints, no upshift or stuck in second from a dead A or B solenoid, harsh or soft shifts from a tired EPC, or intermittent codes from a cracked harness or leaking pressure switch. Replacing every solenoid and the harness in one job saves pulling the pan again for the next part to fail.

On the bench: drop the pan and filter, unplug the pass-through connector and each solenoid, pull the retaining clips and bolts, and remove the pressure switch manifold with its bolts torqued back to spec on install. Check the new pressure switch gasket, lube each solenoid O-ring with ATF before seating it, and route the harness exactly as the old one sat so it clears the filter and pan. After install, clear codes and perform the transmission adaptive relearn with a scan tool, or expect harsh or erratic shifts until it relearns.