Cummins ISX12 CM2250 (2010-12) Fault Code: 3389 PID: 411 SPN: 411 FMI: 16 Exhaust Gas Recirculation (EGR) System- Abnormal Rate of Change

Circuit Description
The Electronic Control Module (ECM) uses the EGR differential pressure sensor reading to determine how much exhaust gas is flowing through the EGR connection tube to the intake manifold. The EGR differential pressure sensor measures the pressure drop across the EGR differential pressure orifice using two exhaust ports. The sensor outputs a voltage, which represents the pressure difference between the two ports, and the ECM correlates that voltage to an EGR flow rate. This information is used to control the EGR valve for correct emission levels.

Component Location
The EGR differential pressure sensor is mounted to the EGR mass measurement assembly.

Conditions for Running the Diagnostics
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is operating.

Conditions for Setting the Fault Codes
The measured EGR flow does not meet the commanded EGR flow for 30 seconds.

Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp and/or Malfunction Indicator Lamp (MIL) after the diagnostic fails on two consecutive trips.
Conditions for Clearing the Fault Code
To validate the repair, start the engine and let it idle for 1 minute.
The fault code status displayed by INSITE? electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
The ECM will turn off the amber CHECK ENGINE lamp after the diagnostic runs and passes.
For On-Board Diagnostic (OBD) engines, the ECM will turn off the MIL after 3 consecutive trips where the diagnostic runs and passes.
The ?Reset All Faults? command in INSITE? electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications

Shop Talk
Possible causes of this fault code include:

A malfunctioning EGR valve
A leaking or malfunctioning EGR differential pressure sensor
A malfunctioning VGT.

Possible Cause:
1) ECM failure