Description The EGR valve is located atop the intake manifold in a port that is machined into the manifold (figure 5-50). A vacuum-operated pintle in the valve controls the amount of exhaust gas that is recirculated into the intake manifold. Recirculating these gases helps reduce emissions. A normally open EGR solenoid controls the EGR valve.… Read More »
EGR CONTROL PRESSURE/BARO SENSOR The EGR control pressure/baro sensor is mounted on the left side of the cowl (figure 5-48). The sensor produces a voltage signal in proportion to the amount of absolute pressure in the EGR vacuum line. The PCM compares this actual signal to the desired EGR value it has calculated and makes… Read More »
The PCM monitors input from the EGR control pressure/baro sensor, APP sensors, crankshaft position sensor (engine speed), and engine coolant temperature to control the amount of exhaust gas that is recirculated back into the intake manifold. Outputs for EGR control consist of the EGR solenoid, EGR vent solenoid, and EGR valve (figure 5-47).
Description On turbocharged engines, the exhaust gases pass from the exhaust manifold through the turbocharger, turning the turbine blades. The compressor side of the turbocharger also turns, pulling air through the air filter and pushing the air into the intake manifold, pressurizing the intake manifold. The turbocharger wastegate is normally closed when the engine is… Read More »
BOOST SENSOR (Turbo Only) Description The boost sensor (figure 5-44) on turbocharged engines measures fluctuations in intake manifold pressure and vacuum that occur as a result of changes in engine load and engine speed. The sensor is a resistor that converts manifold pressure/vacuum into electrical signals: • At idle, the boost sensor displays approxi mately… Read More »
The PCM monitors the APP sensors, engine speed, and intake manifold boost pressure as indicated by the boost sensor to energize the solenoid that controls the turbocharger wastegate valve (figure 5-43).
GLOW PLUG RELAY AND LAMP The glow plug relay is located at the rear of the left cylinder head. When commanded by the PCM, the relay contacts close, allowing ignition voltage to reach the two sets of glow plugs. The PCM uses a B+ signal to control the solid state circuitry of the glow plug… Read More »
The glow plug system assists in providing the heat required to begin combustion during engine starting at cold ambient temperatures. The glow plugs are heated before and during cranking, as well as during initial engine operation. There are three components of the glow plug system: a relay, an instrument panel-mounted lamp, and the glow plugs.… Read More »
Timing on the 6.5L EFI diesel is dependent on three variables: 1. Injection pump position, as indicated by the cam sensor and disc 2. TDC Offset (i.e. crankshaft position sensor) 3. The PCM’s learned values for injection pump timing and TDC Offset Adjusting Injection Timing When a new injection pump is installed, pump timing must… Read More »
Description The injection timing stepper motor is located on the right side of the injection pump. The motor housing contains two coils that are controlled by voltage from the PCM. (See the “Fuel Control” section for a description of stepper motor mechanical and hydraulic operation.) ITS Circuit Operation The injection timing stepper motor contains two… Read More »