Cummins ISB6.7 CM2150 (2007-09) Fault Code: 1866 PID: 411 SPN: 411 FMI: 2 Exhaust Gas Recirculation Valve Delta Pressure – Data Erratic, Intermittent, or Incorrect. An error in the EGR delta pressure signal was detected at initial key-on or the sensor failed the autozero test.

Verify the electronic control module (ECM) calibration is correct. Check the calibration revision history found on Quickserve™ Online for applicable fixes to the calibration stored in the ECM. If necessary, recalibrate the ECM.

This check is only performed at keyswitch OFF, during the ECM powerdown. During this diagnostic check, the ECM monitors the value of the EGR differential pressure sensor. If this value is outside of a specified range, Fault Code 1866 is set active.

Possible causes:

1)A damaged EGR differential pressure sensor
2)High resistance in the wiring harness on the signal or return wire
3)Plugged or restricted EGR differential pressure sensor flow ports.

Possible repairs:

1)Clean the EGR differential pressure sensor flow ports.
2)Replace the EGR differential pressure sensor.
3)Replace the ECM.
4)Replace the engine harness.