Bulletin No.: PI0604C

Date: May-2013

Subject: Information on 6T30/6T40/6T45/6T50 Automatic Transmission Product Updates

Models: 2012-2013 Buick LaCrosse, Regal, Verano

2013 Buick Encore

2012-2013 Chevrolet Captiva Sport, Cruze, Equinox, Malibu, Sonic

2013 Chevrolet Trax

2012-2013 GMC Terrain

Equipped with 6T30, 6T40, 6T45, 6T50 Automatic Transmission (RPOs MHB, MHC, MHH, MHK, MHJ, MH7,

MH8, MH9)

This PI is being revised to update the model information and information under Oil Pump Assembly. Please discard

PI0604B.

A number of product updates have been implemented on the 6T40/6T45/6T50 Automatic Transmission for the 2012 Model Year. These changes are referred

to as Gen 2 in diagnostics and repair instructions and as 2nd design in the parts catalog.

Important: These changes do NOT impact the following 2012 vehicles as they continue to use Gen 1 design.

– 2012 Cruze equipped with 1.8L (LUW)

– 2012 Sonic equipped with 1.8L (LUW)

– 2012 Captiva Sport Equipped with 3.0L (LFW)

– 2012 Orlando

All 2013 vehicles covered by this PI use Gen 2 design transmissions.

Control Solenoid Valve

The control solenoid valve assembly has been modified to remove the fluid pressure switches and their associated DTCs. The following pressure switch DTCs

are not applicable for Gen 2: DTC P0842 or P0843, DTC P0872 or P0873, DTC P0877 or P0878, and DTC P0989 or P0990. Other diagnostics that refer to the

pressure switch states have been modified to remove the reference to the pressure switches.

1

Revised Control Valve Body Filter Plate Assembly (8)

Control Valve Body

2

Addition of Control Valve Body Spacer Plate Retainer (Qty: 2) (406), Actuator Feed Accumulator Spring (Qty: 5) (407), Actuator Feed Accumulator Piston (Qty: 

5) (408), Variable Hi and 2-3-4 Clutch Housing Valve Ball (409) and Control Valve Channel Plate Ball Spring Assembly (434)

3

Addition of Retainer, Low-Reverse and 4-5-6 Clutch Boost Valve and Low-Reverse and 4-5-6 Clutch Boost Valve Spring (435, 436, 437)

4

Revised clutch select valve (428) and Manual Valve (432)

5

Revised Low-Reverse and 4-5-6 Clutch Regulator Valve (411) and 1-2-3-4 Clutch Boost Valve (414)

6

Revised 1-2-3-4 Clutch Regulator Valve (417) and 2-6 Clutch Regulator Valve (419)

7

Revised Default Override Valve (422) and Torque Converter Clutch Regulator Apply Valve (425)

8

Revised 3-5-Reverse Clutch Regulator Valve (421) and addition of 3-5 Reverse Clutch Regulator (Shuttle) Valve (437)

Oil Pump Assembly

9

Revised identification marking of Pressure Regulator Valve (309)

Transmission Case Assembly

10

Removal of one 3-5-Reverse and 4-5-6 Clutch Fluid Seal Ring (58)

Low and Reverse Clutch Assembly

11

Revised identification marking of Low and Reverse Clutch (w/Friction Material) Plate Assembly  (545)

1-2-3-4 Clutch Assembly

12

Revised identification marking of 1-2-3-4 Clutch (w/Friction Material) Plate Assembly (559)

2-6 Clutch Assembly

13

Revised identification marking of 2-6 Clutch Spring (536)

14

Revised identification marking of 2-6 Clutch (w/Friction Material) Plate Assembly (542)

3-5-R clutch Assembly

15

Revised identification marking of 3-5-Reverse Clutch (w/Friction Material) Plate Assembly (509)

4-5-6 Clutch Assembly

16

Revised 4-5-6 Clutch Piston (520), 4-5-6 Clutch Piston Return Spring Assembly (522), 4-5-6 Clutch Piston Fluid Dam Assembly (523) and 4-5-6 Clutch Piston

Fluid Dam Retainer Ring (524)

17

Revised and Relocated 4-5-6 Clutch Piston Outer Seal (519), Revised 4-5-6 Clutch Piston (520), 4-5-6 Clutch Piston Return Spring Assembly (522), 4-5-6

Clutch Piston Fluid Dam Assembly (523) and 4-5-6 Clutch Piston Fluid Dam Retainer Ring (524)

18

Revised quantity and identification marking of Clutch 4-5-6 Clutch (w/Friction Material) Plate Assembly (Qty: 5) (527)

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may

occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools,

safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that

your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

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