DL22 - Check PFE/DPFE Sensor Pressure Input Hose For Blockage

Diagnostic Trouble Code (DTC) 326 or 327 indicates that Differential Pressure Feedback EGR (DPFE) circuit voltage is lower than expected at zero duty cycle.

- Key "OFF".

- Check Pressure Feedback EGR (PFE) / DPFE sensor pressure input hose(s) for obstruction and/or leaks.

- Are there any obstructions or leaks?

Yes -- Service as necessary. Reconnect all lines. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)

No -- Go to DL23. DL23 - Check PFE/DPFE Signal Voltage With Engine at Idle