PACCAR PX-9 CM2350 (2013-17) Fault Code1974 PID:101 SPN:101 FMI:15 Crankcase Pressure – Data Valid But Above Normal Operating Range – Moderately Severe Level

Reason:
Crankcase Pressure – Data Valid But Above Normal Operating Range – Moderately Severe Level. The crankcase breather filter requires maintenance.

Effect:
None on performance.

Circuit Description:
The crankcase pressure sensor is used to monitor the pressure inside the crankcase. The engine control module (ECM) supplies the crankcase pressure sensor a 5 volt reference voltage. When the crankcase pressure is low, the sensor signal voltage is low. When the crankcase pressure is high, the sensor signal voltage is near the 5 volt reference voltage. The ECM monitors the crankcase pressure signal circuit voltage to calculate the pressure of the air within the crankcase.

Component Location:
The crankcase pressure sensor is located near the crankcase ventilation filter.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the engine is operating at idle.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the crankcase pressure reading was higher than a threshold for 60 cumulative minutes at idle.

Action Taken When the Fault Code is Active:
The ECM illuminates the white MAINTENANCE lamp or flashes the amber CHECK ENGINE lamp, indicating a maintenance condition, immediately after the diagnostic runs and fails.

Conditions for Clearing the Fault Code:
1) To validate the repair, start the engine and let it idle for 1 minute.
2) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults.

Shop Talk:
If this fault code is active, the crankcase breather element may need to be replaced.

Possible Causes:
1) Inactive fault codes
2) Bad crankcase ventillation system
3) Faulty ECM