Category Archives: 6.7L Power Stroke

The Front Crank Seal Installer, 303-1509 is used to install the front crankshaft seal.

The Front Crank Seal Remover, 303-1510 is used to remove the front crankshaft seal.

The SCR system reduces nitrogen oxides (NOx) present in the exhaust stream to nitrogen (N2) and water (H2O). The SCR contains a ceramic catalyst washcoated with copper and iron on a zeolite substrate. At the inlet of the SCR catalyst is a port for the reductant dosing module, followed by a grate diffuser and a… Read More »

There is an exhaust mixing system in the exhaust stream to mix the reductant with the exhaust gas. The mixer is made up of an atomizer and a twist mixer. The atomizer breaks up and vaporizes the reductant droplets. The twist mixer evenly distributes the reductant in the exhaust gases for maximum efficiency.

The NOx sensor is used primarily to sense O2 and NOx concentrations in diesel exhaust gas. The sensor is mounted in a vehicle’s exhaust pipe, perpendicular to exhaust gas flow. The sensor is mounted downstream of the SCR and DPF. The sensor interfaces with the NOx sensor module that controls the sensor and heater circuits.

The NOx sensor module is mounted to the vehicle frame under the body. It controls the NOx sensor mounted in the diesel after treatment exhaust system downstream of the SCR and DPF. It communicates to the PCM via the CAN2 to report NOx and O2 concentrations as well as sensor and controller errors.

The PCM monitors the reductant pressure sensor to calculate how much reductant to be injected into the exhaust. The reductant pressure sensor is also be used to shut the pump off when the lines are being drained after the ignition is shut off.

The reductant purge valve is opened by the PCM allowing the pressure to equalize in the fluid tank.

The reductant fluid level sensor operates by using four electrodes (one not visible in the picture) that are mounted on the sensor at different levels. The reductant solution closes the electric circuit between electrodes for each level interface. The signal is then converted before being sent to the PCM.

Below a specified temperature the PCM commands the Glow Plug Control Module (GPCM) to activate the heaters in the reductant system. The reductant system has heaters in the tank, pump, and lines. The heaters in the tank thaw the DEF if it is frozen and allow it to flow to the pump without freezing. The… Read More »