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
External Wiring Harness (Figure 17)
WTEC III uses three external wiring harnesses to provide a connection between the ECU, the
transmission (including engine, turbine, and output speed sensors), the throttle position sensor, the
vehicle interface module (VIM), retarder control module, shift selectors, diagnostic tool connector,
retarder, retarder temperature sensor, accumulator, and vehicle interface. Many harnesses will include
a bulkhead fitting to separate cab and chassis components. Also, many different styles and materials
for harnesses are likely to be encountered.