4T40E Pressure Control Solenoid 1995-2003, new and ready to install. Fits the 4T40E. Ships fast from the USA.
A 1995-2003 Chevrolet Cavalier, Pontiac Sunfire, Chevrolet Malibu or Oldsmobile Alero with a 4T40E that flares on the 1-2 or 2-3 shift, slams into gear, or sets P0748 frequently needs a new electronic pressure control (EPC) solenoid. This is the original large-diameter Delphi-style EPC used through those years. It is an aftermarket replacement listed under reference D84431G and cross-referenced to GM 10478146 and industry number 33946.
The 4T40E has no throttle valve cable, so the only way the computer can raise or lower line pressure is through the EPC. It is a variable force solenoid in its own bore in the valve body, and the current the computer sends it moves the pressure regulator. More throttle and more load bring more pressure to hold the clutches; a light, steady cruise brings less, for smooth shifts. Because one solenoid sets the pressure for every clutch and band, a fault here shows up across several shifts at once. When it reads low, the 2nd and 4th clutches, already the weak spots in this transaxle, get less clamping force and wear quickly. When it sticks high, every engagement and upshift is harsh.
Check the fluid first; burnt, dark fluid with friction material means clutch damage a solenoid will not reverse. Read codes, then measure the EPC circuit at the case connector and at the solenoid itself so a damaged internal harness is not blamed on the part. The best proof is a pressure gauge on the line tap while a scan tool commands EPC current up and down: line pressure should follow smoothly. Our line pressure testing guide shows the gauge hookup, and testing solenoids without a factory scan tool covers resistance and bench checks. Also inspect the pressure regulator bore: TransGo reports that wear in that bore is the most common problem on 1995-on 4T40E and 4T45E units, causing converter codes such as P0741 and P0742, planetary burn-up and burned frictions. If the bore leaks, a new solenoid cannot bring pressure back.
Sonnax documents that GM's 4T40E and 4T45E cars used the large Delphi EPC until the 2004 model year, and that the 2002-2003 GM valve body was fitted with it. The exception is the Saturn L-Series: 2000-2002 cars use this Delphi style, but 2003 L-Series cars switched early to the small Bosch EPC, which we list separately as the 2003-up small Bosch 4T40E EPC. Both styles fit the same bore and plug into the same connector, but Sonnax warns that the wrong one causes harsh shifts or slipping that may not set a code. Compare the diameter of the solenoid you remove with our photo, or send your year and VIN before ordering. More parts are in the 4T40E collection.
Drain the fluid and remove the pan to reach the valve body, then follow your service manual to release the EPC retainer and pull the old solenoid. Clean the bore, look for scoring, and lube the new O-rings with fresh fluid so they do not tear on the way in. If the valve body has worn bores or you are fighting several solenoid faults, a complete remanufactured 4T40E valve body for 2003 may be the better repair. Refill with Dexron VI, check the level hot, and clear the transmission adaptive values with a scan tool so the computer learns the new solenoid over several drive cycles.
| Fits | 4T40E 1995-2003 |
| Part type | Pressure Control Solenoid |
| Condition | New |
| Brand | OEM |
| Reference | D84431G |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Most likely yes. Sonnax notes GM's 4T40E cars, apart from the Saturn L-Series, kept the large Delphi EPC through 2003 and switched to the small Bosch style in 2004. Compare your old solenoid with our photo to be sure.
No. Saturn L-Series cars changed to the small Bosch EPC in 2003. Use the 2003-up small Bosch 4T40E EPC instead; 2000-2002 L-Series cars use this Delphi style.
Yes, for the same years. The 4T40E and 4T45E share the valve body and EPC design, and the Delphi-to-Bosch change happened on both at the same time.
Dexron VI ATF, checked at operating temperature. Low or degraded fluid will make even a new EPC solenoid produce poor shift quality.
A new filter and pan gasket at minimum. If you see scoring in the EPC or pressure regulator bores, plan for a valve body repair, since a worn bore leaks pressure that a new solenoid cannot make up.
