Replaces the shift, TCC and pressure control solenoids in GM 4T40E and 4T45E transaxles that cause harsh 1-2 shifts and limp mode.
If your Cobalt, HHR, G5, G6, Ion, Malibu or Cavalier bangs into second, flares on the 2-3, shudders at light throttle or sits in second-gear limp mode with a shift solenoid code, the electrical side of the 4T40E or 4T45E valve body is the first place to look. This remanufactured kit replaces that whole side at once for 2004-2010 GM front-drive cars: the two shift solenoids, the torque converter clutch (TCC) solenoid, the pressure control (EPC) solenoid, and the pressure switch manifold shown in the product photos. Each piece is tested before it ships and may carry light cosmetic marks.
The 4T40E (RPO MN4) and the heavier-duty 4T45E (RPO MN5) are four-speed transaxles run entirely by the engine computer. Shift solenoids A and B are simple on/off valves; the computer switches them in combinations to select each gear. The EPC solenoid is a variable force motor that sets line pressure, which decides how firmly every clutch and band is squeezed. The TCC solenoid locks and unlocks the converter at cruise, and the pressure switch manifold tells the computer which range the manual valve is in. When one of these goes weak, the computer commands a shift that the hydraulics never deliver.
Check the fluid level and condition first; burnt, black fluid means clutches are already damaged and solenoids alone will not fix the slip. Then read every stored code, not just the first one. An electrical code (P0753, P0758) can be a broken wire or a cracked internal harness, so measure each solenoid's resistance at the case connector and again at the solenoid; our multimeter solenoid testing guide walks through it. Converter codes P0741 and P0742 deserve extra care on this unit: TransGo documents pressure regulator bore wear on every 4T40E and 4T45E from 1995 on as a cause of those codes, burnt frictions and overheating, and a new TCC solenoid will not cure a worn bore. If the bore is the problem, a replacement 4T40E valve body is the real fix.
The listing covers 2004-2010 vehicles: 2004-2005 Chevrolet Cavalier 2.2L, 2005-2010 Cobalt 2.0L, 2008-2010 HHR 2.0L, 2004-2008 Malibu 2.2L, 2004 Oldsmobile Alero 2.2L, 2007-2009 Pontiac G5 2.2L, 2006-2010 G6 2.4L, 2004-2005 Grand Am and Sunfire 2.2L, 2007-2008 Saturn Aura 3.5L, 2005-2007 Ion 2.0L and 2005 L300 3.0L. The listing also names the 2005 Buick Century 3.1L and 2004-2005 LeSabre 3.8L; many of those cars left the factory with the larger 4T65E, so check the transmission RPO code (MN4 or MN5) on the glovebox or trunk build label before ordering.
Year matters for the EPC solenoid. Sonnax notes that GM 4T40E/4T45E valve bodies through 2003 use a large Delphi EPC, while 2004 and later use a small Bosch EPC. Both fit the same bore and plug, so the wrong one installs easily: a Delphi in a 2003-or-later unit gives soft, slipping shifts, and a Bosch in a 2000-2002 unit gives harsh shifts that may not adapt out. Saturn changed a year early, in 2003. If you are unsure, send us your year and VIN, or browse the full 4T40E and 4T45E parts collection.
This is a pan-down job with the transaxle in the car. Drain the fluid, remove the pan and filter, and unplug the internal harness from each solenoid and the manifold. Note where each solenoid came from before you pull the retaining bolts. Lube the new O-rings with clean ATF, push each solenoid into its bore by hand so it sits square, and torque the bolts evenly; a cocked solenoid is the most common reason a new part codes out immediately. Inspect the harness while it is exposed, because a heat-hardened or chafed harness causes the same codes as a bad solenoid; the 4T40E internal wiring harness is the part to swap if the insulation cracks when you flex it. Fit a new filter and pan gasket, refill with DEXRON VI, check the level hot, then clear codes and reset the shift adapts so the computer relearns clutch apply with the new parts. If the fluid came out full of friction material, plan on a 4T40E master rebuild kit instead of solenoids alone.
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Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
It is listed for 2004-2010. GM 4T40E and 4T45E units through 2003 use the large Delphi EPC solenoid, and this 2004-up kit is built around the small Bosch style. Putting the wrong EPC in causes soft or harsh shifts, so confirm your year before ordering.
Yes. Both transaxles share the solenoid layout in these years. The 4T40E is RPO MN4 and the 4T45E is MN5; check the code on your vehicle's build label to be sure you do not have a 4T65E.
DEXRON VI. Refill to the cold mark, run the engine, and check the level again with the fluid at operating temperature.
Yes. Clear the codes and reset the transmission shift adapts with a scan tool, then drive through all gears at light and moderate throttle so the computer relearns clutch fill times with the new parts.
Only if the solenoid is the cause. On the 4T40E and 4T45E, pressure regulator bore wear is a documented cause of P0741 and P0742. If the code returns with a new solenoid, the valve body needs attention.
A filter and pan gasket every time, and the internal wiring harness if its insulation is brittle or the connectors are cracked.
