SECTION 1 -- GENERAL DESCRIPTION

WTEC III ELECTRONIC CONTROLS TROUBLESHOOTING MANUAL

SECTION 1 -- GENERAL DESCRIPTION

11.

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 HD 4070

have up to seven forward ranges and one reverse range.

Figure 11 is a block diagram of the basic system inputs and outputs.

SHIFT SELECTOR

RANGE AND

DISPLAY

MODE SWITCH

OIL LEVEL SENSOR

SPEED SENSORS

SOLENOIDS

THROTTLE POSITION SENSOR

ECU

RETARDER MODULATION

C3 PRESSURE SWITCH

VEHICLE/ENGINE

TEMPERATURE SENSOR

COMMUNICATION LINKS

(SUMP/RETARDER)

VIM

INPUTS

OUTPUTS

V03469

Figure 11. Electronic Control Unit Block Diagram

Figure 12 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

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