Cummins ISX12 CM2250 (2010-12) Fault Code: 779 PID: SID 51 SPN: 703 FMI: 11 Auxiliary Equipment Sensor Input 3- Root Cause not Known

Circuit Description
The original equipment manufacturer (OEM) has the option of wiring a pressure or temperature sensor input to the Cummins? electronic control module (ECM). A specific calibration is then created to recognize this pressure or temperature sensor input. This fault code is activated when the pressure or temperature input from the OEM sensor exceeds the engine protection limit defined by the OEM. Depending on OEM requirements, an Engine Protection derate can be associated with this fault code.

Component Location
The OEM pressure or temperature sensor input will vary, depending on application. Refer to the OEM service manual for sensor location.

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

Conditions for Setting the Fault Codes
The ECM detects that the engine protection limit for the OEM input device has been exceeded.

Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE light immediately when the diagnostic runs and fails.
Engine power can be limited, depending on the specific OEM calibration.
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.
The ?Reset All Faults? command in INSITE? electronic service tool can be used to clear active and inactive faults.

Shop Talk
This fault code is activated when the pressure or temperature input from the OEM sensor exceeds the engine protection limit defined by the OEM. An engine power derate is possible, depending on the OEM application.

Possible Cause:
1) N/A