Page 52 - Hydra-matic 6 Speed RWD Technician's Guide (October 2005)

ELECTRICAL COMPONENTS

TRANSMISSION FLUID PRESSURE SWITCH 1, 3, 4 AND 5

SEAL

DIAPHRAGM

PISTON

TFP UPPER
SWITCH 4 CONTACT
TFP
SWITCH 1
TFP DISK
SWITCH 3 TFP
SWITCH 5
LOWER
CONTACT
Body Seal
Upper
Contact Diaphragm

+
The transmission fluid pressure switches located in the control
solenoid valve assembly are normally-closed. When closed,
these switches allow electric current to flow through the switch.
Ground
Lower Fluid Pressure Switch Operation:
Disk Piston Contact The fluid pressure switches are normally closed (contacts touch-
NO PRESSURE ing) when no fluid pressure is present, thereby allowing electri-
cal current to flow through the switch. When fluid pressure is
Body Fluid Seal routed to the switch, the fluid pressure moves the diaphragm,
Upper piston and disk such that the circuit opens (no current flow).
Contact Diaphragm
TFP switch 1 sends a signal to the TCM to indicate the state of
the 3-5 and reverse clutch regulator valve.
+ TFP switch 3 sends a signal to the TCM to indicate the state of
the 2-6 clutch regulator valve.

TFP switch 4 sends a signal to the TCM to indicate the state of
Ground the 1-2-3-4 clutch regulator valve.
Lower
Disk Piston Contact
TFP switch 5 sends a signal to the TCM to indicate the state of
PRESSURIZED the CBR1 / 4-5-6 clutch regulator valve.
Fluid Pressure Switch Logic The transmission fluid pressure switches are part of the control
solenoid (w/body and TCM) valve assembly and are not ser-
Gear Selector Position Switch 1 Switch 3 Switch 4 Switch 5 viced separately.
Park 1 0 0 0
Reverse 0 0 0 0
Neutral 1 0 0 0
Drive 1 Engine Braking 1 1 0 0
Drive 1 1 1 0 1
Drive 2 1 0 0 1
Drive 3 0 1 0 1
Drive 4 1 1 0 0
Drive 5 0 1 1 0
Drive 6 1 0 1 0
1 = Pressurized 0 = Exhausted

Figure 39 43