EGR Pintle Positions

Closed Valve Pintle Position

At key-on, the PCM sets the closed valve pintle position to 103 counts. Since the EGR valve pintle will not close to 0 counts, the PCM uses 103 counts as a reference point. The closed valve pintle position is updated only when the actual pintle position falls below 103 counts. If the closed valve pintle position is measured above 103 counts, the PCM will set a diagnostic trouble code. A DTC will also set if the pintle position falls below 9 counts. Closed valve pintle positions outside of this range indicate a pintle position sensor failure. Once the closed valve pintle position is established, the PCM uses this information to calculate the normalized pintle position.


Normalized Pintle Position

After the closed valve pintle position is established, the PCM calculates a normalized pintle position. The normalized position is the difference between the actual pintle position and the closed valve pintle position multiplied by a scaling factor. The PCM uses the normalized pintle position to determine the desired pintle position for maximum EGR performance.


Desired Pintle Position

The desired pintle position is the result of computations performed by the PCM using various inputs such as engine speed, intake manifold temperature and pressure, air flow, and engine coolant temperature, and stored calibrations from the PCM EPROM. By continuously computing the desired pintle position, the PCM can vary EGR flow for particular driving conditions.

The PCM calculates pintle position error, desired pintle position minus normalized pintle position, to determine if it is accurately controlling EGR flow. If the pintle position error exceeds 25 counts for more than 10 seconds, the PCM will set a diagnostic trouble code.