4
AFLR M- -1
4 13 9
14
15 7
J44-718
1.
Selector 2. Mode switch 3. Rotary switch
4. Transmission control unit 5. Output shaft speed sensor 6. Kick-down switch 7. Battery
8. Transmission relay
9.
10.
11.
12.
13.
14.
15.
16.
Transmission control module (TCM)
Reverse lamps
Start inhibiter
Engine speed
Ignition retard
Engine load
Engine control module
(ECM) Engine speed sensor
Fig.
1 Control Layout Schematic
2.1.5 Transmission Control Module (TCM)
The Transmission Control Module (TCM) is an electronic control unit located in the front passenger footwell behind
the underscuttle pad. It is electrically connected to the transmission and other components through a cable harness
and multiple pin plug.
The TCM continuously monitors the gear selected (via the rotary transmission switch), the speed of the output shaft
(by speed sensor on the output shaft) and throttle position ('kick
-down' switch). This information plus input from the
Engine Control Module (ECM) of throttle angle and engine speed and load in conjunction with a pre-programmed con- trol map, enables the most suitable gear to be selected.
The TCM, by operating solenoid valves
MVI, MV2 and MV3, controls the gear shift speed and in conjunction with the
solenoid operated pressure control valve, controls the gear shift quality. Gear shift quality on upshifts is improved by
the TCM momentarily retarding the ignition to reduce the torque input as the gear change takes place. Information
is fed to the TCM from sensors and
if any electronic component fails, the basic shift changes will be performed by the
hydro-mechanical system, ie Park, Reverse, Neutral, D3 or D4.
46
Issue 1 August 1994
