Automatic Transmission

System description (cont'd)

14-55  

Hydraulic Flow

As the engine turns, the ATF pump starts to operate. Automatic transmission fluid (ATF) is drawn through the ATF strainer and discharged into the hydraulic circuit. Then, ATF flowing from the ATF pump becomes line pressure that's regulated by the regulator valve. Torque converter pressure from the regulator valve enters the torque converter through the lock-up shift valve and it is discharged from the torque converter. The torque converter check valve prevents torque converter pressure from rising.

The PCM controls the shift solenoid valves A and B ON and OFF and shift solenoid valves A and B apply modulator pressure to the shift valves. Applying modulator pressure to the shift valves moves the position of the shift valve and switches the port of hydraulic pressure. The PCM also controls the A/T clutch pressure control solenoid valves A and B. The A/T clutch pressure control solenoid valve A regulates linear solenoid pressure and applies linear solenoid pressure to the CPC valves. The CPC valve regulates CPC pressure and controls to shift smoothly between upper and lower gears.

Hydraulic pressure at the port is as follows:

PORT NO. DESCRIPTION OF PRESSURE PORT NO. DESCRIPTION OF PRESSURE
1 LINE 15 1ST-HOLD CLUTCH
1' LINE 16 1ST-HOLD CLUTCH
1" LINE 17 1ST-HOLD CLUTCH
2 LINE 18 1ST-HOLD CLUTCH
3 LINE 20 2ND CLUTCH
3' LINE 20A 2ND ACCUMULATOR
3" LINE 30 3RD CLUTCH
4 LINE 40 4TH CLUTCH
4' LINE 41 4TH CLUTCH
4" LINE 56 LINEAR SOL A
5 CPC 90 TORQUE CONVERTER
6 MODULATOR 91 TORQUE CONVERTER
6A MODULATOR (SH A) 92 TORQUE CONVERTER
6B MODULATOR (SH B) 93 ATF COOLER
6C MODULATOR (LC A) 94 TORQUE CONVERTER
6E LINEAR SOL B 95 LUBRICATION
6E' LINEAR SOL B 96 TORQUE CONVERTER
7 LINE 97 TORQUE CONVERTER
8 LINE/CPC 99 SUCTION
9 LINE X DRAIN
10 1ST CLUTCH HIX HIGH POSITION DRAIN

Key to abbreviations: