Cummins ISB CM850 (2003-06) Fault Code: 1671 PID: SPN: 1761 FMI: 1 Catalyst Tank Level ? Data Valid but Below Normal Operational Range ? Moderately Severe Level. Low catalyst solution level has been detected in the catalyst solution tank.

Cummins ISB CM850 (2003-06) Fault Code: 1671 PID: SPN: 1761 FMI: 1 Catalyst Tank Level ? Data Valid but Below Normal Operational Range ? Moderately Severe Level. Low catalyst solution level has been detected in the catalyst solution tank.

Fault code 1671 is triggered when low catalyst solution level has been detected in the catalyst solution tank. Add catalyst solution to the tank. This fault code is only a warning for low catalyst tank solution level.

On-Board Diagnostic (OBD) Information:

1)The ECM illuminates the appropriate amber or red fault lamp when the diagnostic runs and fails.
2)The ECM turns off the appropriate fault lamp when the diagnostic runs and passes.

Possible repairs:

1)Add catalyst solution to the catalyst solution tank.