CHERY AUTOMOBILE CO., LTD Automatic Transmission Fault Diagnosis Manual
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6. Throttle pressure regulator
The throttle pressure regulator is a relief valve and adjusts the oil pressure in the throttle oil circuit
when the throttle valve is at different positions.
Idle position
The accelerator pedal is in free condition. The throttle valve’s piston is at the start point and the
throttle valve doesn’t have any oil pressure.
Parking position
Step down the accelerator pedal a little bit. The throttle valve’s piston moves from the start point to
position 1 and adjusts the oil pressure in the throttle valve during this process.
WOT position
Step down the accelerator pedal and the throttle cam moves to kickdown position. The throttle
valve works at position 1 and the piston moves until position 2. The throttle valve’s oil pressure is
regulated during this process.
Kickdown position
Step down the accelerator pedal to full and the throttle cam moves beyond the kickdown position.
The throttle valve works at position 2.
7. Gearshift valve
Each gear position has a gearshift valve.
The gearshift control element controls the oil circuit so to control which shift valve is working. The
shift valve closes or opens the valve chamber in accordance with the oil pressure control valve
spindle’s moving. The time when the shift moves from position 1 to 2 is related with the linear,
governor and throttle oil pressure.
8. Shuttle valve
The shuttle valve protects the control element from impact when the oil pressure changes
dramatically to ensure smooth gearshift and prevent shift impact.
9. Shuttle valve and clutch control valve
The position of accelerator pedal or action of the engine output torque control shuttle valve depends
on the pressure regulator valve for oil pressure output. Each clutch control valve works as a relief
valve to control the oil pressure required by the clutch at gearshift.
10. Oil capacity shuttle valves
These shuttle valves are irrelevant with oil capacity and the oil pressure is not controlled by the
main pressure regulator valve. They depend completely on the spring for buffer.
1
st
and back gear lock valve
1
st
and back gear lock valves has two functions:
1. Prevent the engagement of back gear when the vehicle speed has not been lowered down, close
clutch B and brake D’s control oil circuit; this function is realized through the governor and
linear oil pressure.
2. When the control handle is in position 1, the lock valve controls the linear oil pressure at 1
st
-2
nd
shift valve and prevent it from upshift to 2
nd
gear. Hence, the vehicle speed is limited within the
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