Page 53 - Hydra-matic 6 Speed RWD Technician's Guide (October 2005)

ELECTRICAL COMPONENTS

SHIFT SOLENOIDS
The Hydra-matic 6 Speed RWD uses two electromagnetic PLUNGER
shift solenoids (1 and 2) to control the two clutch select AND
valves 2 and 3. The shift solenoids are part of the control METERING COIL
BALL
solenoid (w/body and TCM) valve assembly and are not ASSEMBLY ASSEMBLY CONNECTOR
serviced separately. SUPPLY
PRESSURE
The shift solenoids are identical, normally-closed, 3-port, ON/ (ACTUATOR
OFF type solenoids controlled by the TCM. These shift FEED LIMIT)
solenoid work in combination with the pressure control
solenoids to control the various shift and clutch regulator
valves. The TCM uses numerous inputs (as shown in Figure
35) to determine which solenoid state combination the
transmission should be in. The following table shows the CONTROL EXHAUST
solenoid state combination required for each gear range: PRESSURE

Gear SS 1 SS 2
Park ON ON
SPRING HOUSING
Reverse ON OFF
Neutral ON ON NORMALLY-CLOSED ON/OFF SOLENOID
Drive 1 Engine Braking ON ON
Drive 1 OFF ON
Drive 2 OFF ON
Drive 3 OFF ON
Drive 4 OFF ON
Drive 5 OFF ON
Drive 6 OFF ON

Shift Solenoid (SS) 2:
When the TCM provides a path to ground for the electrical Actuator feed limit fluid feeds the shift solenoid 2 fluid circuit
circuit to energize (turn ON) the solenoid, current flows through to control the clutch select valve 3. When the SS 2 valve is
the coil assembly in the solenoid and creates a magnetic field. energized (ON), actuator feed limit fluid is allowed to pass
The magnetic field moves the plunger and metering ball assembly through the solenoid, thereby creating solenoid 2 fluid pressure
to the right (with respect to the illustration) against the exhaust (see example). Solenoid 2 fluid pressure acts against the clutch
seat, thereby blocking the exhaust passage and creating signal select valve 3 spring force to move the valve to the apply
fluid pressure. position.

The shift solenoids are de-energized (turned OFF) when the When the SS 2 is de-energized (OFF), actuator feed limit fluid
TCM opens the path to ground for the solenoid’s electrical is blocked from feeding the solenoid 2 fluid circuit, and any
circuit. With the solenoid OFF, solenoid spring force moves existing solenoid 2 fluid pressure exhausts through the solenoid.
the plunger and metering ball assembly away from the exhaust
seat and against the feed seat. This blocks actuator feed limit
fluid from entering the signal fluid circuit and allows any existing
REVERSE
signal fluid pressure to flow past the metering ball and exhaust
SOL 1
out of the solenoid as shown in the illustration. #2
Shift Solenoid (SS) 1: N.C. 35 REV CL CSV2 ENABLE
Actuator feed limit fluid feeds the shift solenoid 1 fluid circuit SHIFT DRIVE EX DRIVE
to control the clutch select valve 2. When the SS 1 is energized SOL 1 SOL 1 EX EX 22
OFF
(ON), actuator feed limit fluid is allowed to pass through the ACT FD LIM CLUTCH SELECT VALVE 2
solenoid, thereby creating solenoid 1 fluid pressure (see example). EX
Solenoid 1 fluid pressure acts against the clutch select valve 2 DRIVE 1-6
spring force to move the valve to the apply position. CSV2 LATCH
CBR1/456 CL FD
When the SS 1 is de-energized (OFF), actuator feed limit fluid CBR1/CBR FD
is blocked from feeding the solenoid 1 fluid circuit, and any
existing solenoid 1 fluid pressure exhausts through the solenoid. CBR1/CBR FD
REVERSE DRIVE BRAKE DRV B EX REVERSE 456 CL FD EX 21 1234 CL DFLT 1234 CL DFLT FD

CLUTCH SELECT VALVE 3
20
456 CL
ACT FD LIM CBR
35 CL REV FD 35 CL REV FD CSV3 ENABLE 456 CL
N.C.
SHIFT
SOL 2 #3
ON
SOL 2 SOL 2

44 Figure 40