Ditch Witch RT115 Q - Manual (Page 165)

Service - 164
RT115Q Operator’s Manual
Tier 3 Engine
Tier 3 Engine
Tier 3 is a computer-controlled fuel management system. A variety of sensors send input data to an ECU
(Electronic Control Unit) that compares inputs with pre-programed memory and sends output voltage to a
variety of actuators to adjust and operate the engine within specified parameters.
The system is self-diagnostic with stored trouble codes displayed on the tachometer/diagnostic gauge or
read directly from a diagnostic connector. For more information about the diagnostic system and trouble
codes see "Troubleshooting" in the repair guide.
An operator alert indicator tells the operator when warning faults or engine shutdown faults develop.
Warning faults occur when engine sensors indicate moderate trouble with coolant temperature, oil
pressure, charge air temperature, or fuel temperature. Warning faults cause the operator alert indicator to
flash, and the engine will begin a slow power derate. In some situations an alarm may also sound. A
trouble code is stored in the ECU. If the fault corrects itself, the engine will gradually return to normal
power. The alert indicator will continue to flash until the trouble goes away, but a trouble code will remain
stored.
Engine shutdown will occur due to severe faults in engine coolant temperature, oil pressure, or fuel
temperature. Before shutdown, the operator alert indicator will light continuously and the engine will begin
a rapid power derate. If the fault does not improve in 30 seconds the engine will shut down.
Engine Diagnostic Codes
Problems with the Tier 3 engine usually are indicated by the operator alert indicator and by a diagnostic
code displayed on the tachometer/hourmeter/diagnostic gauge.