Cummins ISB CM850 (2003-06) Fault Code: 1711 PID: SPN: 3361 FMI: 9 Dosing Control Unit Data Link ? Abnormal Update Rate. Data Link communications between the ECM and the Dosing Control Unit have been interrupted.

Posted by PerDiezel Solutions on January 18, 2026

Possible causes:

1)Loss of battery voltage to the Dosing Control Unit
2)Loss of battery ground to the Dosing Control Unit
3)Loss of keyswitch input to the Dosing Control Unit
4)Shorted or open J1939 data link wiring between the Dosing Control Unit and the primary engine ECM
5)Failed Dosing Control Unit
6)The external OEM controlling device has failed or can no longer transmit on the data link.

On-Board Diagnostics (OBD) Information (Euro 4 Certified Engines):

1)The ECM illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
2)The ECM turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. The MIL lamp and fault code can also be cleared using the INSITE? Electronic service tool.
3)The fault code will be cleared from memory after 40 consecutive drive cycles where the diagnostic runs and passes.

On-Board Diagnostics (OBD) Information (Euro 4 Stage 1+ Certified Engines):

10The ECM illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
2)An engine torque derate will be activated after 50 hours of engine operation with the fault code active.
3)The ECM turns OFF the malfunction indicator lamp (MIL) after 1 ignition cycle that the diagnostic runs and does not fail. The MIL lamp cannot be cleared using the INSITE? Electronic service tool.
4)The fault code will be cleared from memory after 400 days or 9600 hours of engine operation.

Possible repairs:

1)Repair or replace the OEM harness.
2)Replace the dosing control unit.

Cummins ISB CM850 (2003-06) Fault Code: 1699 PID: SPN: 1761 FMI: 2 Catalyst Tank Level Sensor – Data Erratic, Intermittent, or Incorrect. Catalyst solution level is not changing with engine operating conditions.

Cummins ISB CM850 (2003-06) Fault Code: 1698 PID: SPN: 3489 FMI: 4 Aftertreatment #1 Air Enable Actuator ? Voltage Below Normal, or Shorted to Low Source. Low signal voltage has been detected at the catalyst air solenoid circuit.

Cummins ISB CM850 (2003-06) Fault Code: 1697 PID: SPN: 3489 FMI: 3 Aftertreatment #1 Air Enable Actuator ? Voltage Above Normal, or Shorted to High Source. High signal voltage has been detected at the catalyst air solenoid circuit.

Cummins ISB CM850 (2003-06) Fault Code: 1694 PID: SPN: 3234 FMI: 2 Aftertreatment Outlet NOx Sensor – Data Erratic, Intermittent, or Incorrect. An incorrect NOx sensor reading has been detected by the aftertreatment outlet NOx sensor.

Cummins ISB CM850 (2003-06) Fault Code: 1692 PID: SPN: 3234 FMI: 4 Aftertreatment NOx Sensor – Voltage Below Normal, or Shorted to Low Source. Out-of-range battery voltage has been detected by the aftertreatment outlet NOx sensor.

Cummins ISB CM850 (2003-06) Fault Code: 1689 PID: 251 SPN: 251 FMI: 12 Real-Time Clock Power Interrupt – Data Erratic, Intermittent or Incorrect. The Real-Time clock power has been interrupted.

WARNING!