Diesel Throttle Valve
A Throttle Valve
A throttle valve is necessary for all diesel engines equipped with a particulate filter system. The throttle valve chokes the intake air to increase EGR air flow to ensure that the exhaust gas temperature is increased for the required regeneration of the particulate filter and smooth engine shut off.
This photo shows the seal failure on the throttle valve allowing oil vapors to enter and accumulate in the throttle valve housing and, over time, short the motor activation input circuit to ground. This turns on the Service Engine Soon light, and the system goes into failsafe full open position.