Ex Park (engine running) Ex Ex Air bleed Line Line Line Torque sig CC signal AFL AFL AFL AFL AFL AFL AFL Rev input Cooler Press relief valve Pump asm. Filter Sump ExConv Ex Apply Reg ap Reg apply Isolator Release Rev input 3-4 cl 3-4 cl 3-4 cl 3-4 cl 3-4 acc Orf acc 3rd acc 3rd acc Ex Ex 2nd cl 2nd cl 2nd cl 2nd 2nd Acc Accum Accum O’run cl 3-2 control 3-4 relay 3-4 shift valve Acutuator feed limit Rev abuse Accum valve 3-2 downshift 4-3 sequence valve Overrun cl Rev input Fwd cl feed Filter Overrun cl fd Overrun cl fd Actuator feed limit 3-4 sig 3-4 sig 3-4 sig 3-4 acc 3-4 acc 4th 14 4th Rev 4th sig Rev inp Rev input Servo fd 3-4 acc 2nd D4-3-2 Forward abuse 1-2 shift valve 2-3 shift valve 2-3 shuttle Lo overrun Line D4 D4 Lo D3 D2 Pr Pr Pr Ex Ex 3-4 clutch Apply Cooler Torque converter assembly Lube Reverse input clutch assembly Fwd cl feed Fwd cl fd Input clutch housing assembly Lo & reverse clutch assembly Intake & decrease Converter & lube Mainline Solenoid sig. Accumulator Actuator feed Torque signal Lo/rev D4 D4 D4 Lo/1st Sig A Sig A Sig A Lo Pr TCC solenoid N.O. TCC PWM Sol (N.C.) Filter Pressure control solenoid 1-2 sol N.O. ON 2-3 sol N.O. ON 3-2 cont sol N.C. 1-2 accumulator 3-4 accumulator Pressure switch assembly D2-N.C. D3-N.C. Rev-N.O. Lo-N.O. D4-N.O. Temp sensor D 3 2 1 NRP Manual valve Line pressure tap 2 1 10 19 18 4 11 12 13 #1 #7 #2 #4 6 7 5 #3 17 32 31 #8 30 16 8 9 #10 #12 22 23 27 25 26 21 28 29 #5 #6 2nd & 4th servo 24 Chapter 12 Electronic Control Systems 283 Copyright by Goodheart-Willcox Co., Inc. Decrease Intake Line Rev input Press reg. Boost alvev fd Rev input Rev input Converter clutch valve Reg ap Ex Ex Ex Ex Ex Ex Ex Ex Ex Ex Ex Ex Ex Ex Release Rev input 3-4 cl 3-4 cl 3-4 cl 3rd acc Ex Overrun cl Overrun cl fd Reverse Rev 3-4 sig 4th Servo fd 2nd 2nd Pr Line Pr Pr Lo/rev D3 D3 D2 Lo D4 D3 D3 D3 Orun D2 D2 D2 Ex Ex Ex Ex Ex Ex Ex Ex Ex Ex Forward clutch feed Overrun clutch Apply Lube Fwd cl fd Fwd cl fd Lo/rev D4 D4 Lo Lo Rear lube Figure 12-30. Oil flow schematic of an electronically controlled, four-speed, rear-wheel drive transmission. The transmission is in Park and the engine is running. Study the components in this schematic before proceeding. (General Motors)