Cummins ISX11.9 CM2250 (2010-12) Fault Code: 6337 PID: SPN: 862 FMI: 4 Crankcase Breather Filter Heater Circuit- Voltage Below Normal or Shorted to Low Source

Circuit Description
The crankcase breather heater is used to keep the crankcase breather filter housing from freezing. The engine control module (ECM) supplies battery voltage to the breather heater when heating is commanded.

Component Location
The crankcase breather heater is mounted to the crankcase breather filter housing.

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

Conditions for Setting the Fault Codes
The ECM detected the crankcase breather heater signal circuit was shorted to ground.

Action Taken When the Fault Code is Active
The ECM logs the fault code immediately when the diagnostic runs and fails.
The crankcase breather heater will be disabled.
Conditions for Clearing the Fault Code
To validate the repair, perform a key cycle, 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 Reset All Faults command in INSITE? electronic service tool can be used to clear active and inactive faults, as well as extinguish the malfunction indicator lamp for on-board diagnostics applications.

Shop Talk
Possible causes of this fault code include:

Open crankcase breather heater circuit
Short circuit to ground in the crankcase breather heater circuit
Malfunctioning ECM.

Possible Cause:
1) Crankcase breather filter failure
2) Engine Harness
3) ECM calibration