Service Manual

627333-A 3-19
Transmission and Solenoids
Maximum Signal Current (Clutch Fully Engaged)
Modulating Valve
1. Modulating Valve;
2. Test Port;
3. Clutch;
4. Spring;
5. Line to Sump;
6. Spool Orifice;
7. Charge Pressure Oil;
8. To Transmission Clutch;
9. Solenoid;
10. Ball;
11. Valve Spool;
12. Drain Orifice;
13. Pin;
14. Charge Pressure;
15. Sump;
When the modulation cycle stops, the transmission
ECM will send the maximum specified signal current in
order to fully engage the transmission.
The constant signal current pushes pin (11) firmly
against ball (10) in modulating valve (1).
The force against the ball reduces the amount of oil flow
through drain orifice (12). This restriction causes an
increase in pressure on the left side of valve spool (13).
The valve spool moves to the right to allow the charge oil
to fully engage the transmission clutch.
In a short period of time, maximum pressure is felt at
both ends of the valve spool. This pressure and the
additional force that is produced by spring (4) causes the
valve spool to move to the left until the forces on the right
end and the left end of the valve spool are balanced.
The movement of the valve spool to the left balanced
position reduces the flow of oil to the engaged
transmission clutch. The transmission ECM sends a
constant maximum specified signal current to solenoid
(8) in order to maintain the desired clutch pressure.
FIG. 18
Q000042S
10
6
1
2
13
4
7
3
5
12
11
8
14
15