Cummins ISX12 CM2250 (2010-12) Fault Code: 698 PID: 21 SPN: 1136 FMI: 4 Engine ECU Temperature Sensor Circuit- Voltage Below Normal, or Shorted to Low Source

Circuit Description
The electronic control module (ECM) has an internal temperature sensor that is used to measure the temperature inside the ECM.

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 internal temperature sensor circuit is shorted to ground.

Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic runs and fails.
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 sensor is located internally to the ECM. No troubleshooting is possible for this fault code. If the fault code is active, the ECM must be replaced.

Possible Cause:
1) ECM calibration