W T E C I I I E L E C T R O N I C C O N T R O L S T R O U B L E S H O O T I N G M A N U A L
0011 00-13
1–1.
TRANSMISSION
The World Transmission Electronic Controls (WTEC III) system features closed-loop clutch control to provide
superior shift quality over a wide range of operating conditions. MD 3000, HD 4000, and B Series configurations
can be programmed to have up to six forward ranges, neutral, and one reverse range. The MD 3070 and HD4070
have up to seven forward ranges and one reverse range.
Figure 1–1 is a block diagram of the basic system inputs and outputs.
Figure 1–1. Electronic Control Unit Block Diagram
Figure 1–2 shows WTEC III electronic control components.
WTEC III Electronic Controls consist of the following elements:
•
Remote 12/24V Max Feature Sealed Electronic Control Unit (ECU)
•
Remote Pushbutton or Lever Shift Selector
•
Optional Secondary Shift Selector
•
Throttle Position Sensor (TPS) (or electronic engine throttle data or PWM signal)
•
Engine, Turbine, and Output Speed Sensors
•
Control Module (Electro-Hydraulic Valve Body)
•
Wiring Harnesses
•
Vehicle Interface Module (VIM)
•
Autodetect Feature
•
TransID Feature
•
Optional Retarder Controls
•
Optional Engine Coolant Temperature Input
NOTE:
•
All external harnesses are OEM supplied
•
Some OEMs may supply their own shift selector
•
The VIM is an OEM option
SECTION 1 — GENERAL DESCRIPTION
