CM850 Electronic Control System – FAULT CODE 296lrv

Crankcase Pressure – Data Above Normal Operational Range – Severe Level


Fault Code: 296lrv
PID: 443
SPN: 1388
FMI: 14

Crankcase Pressure – Data Above Normal Operational Range – Severe Level.

Engine power derate.

ISL Recreational Vehicles – Crankcase Pressure Sensor Circuit

Circuit Description

The pressure inside the crankcase is measured by the crankcase pressure sensor. When the crankcase pressure sensor determines that the crankcase pressure is higher than normal, this fault code is logged.

Component Location

The crankcase pressure sensor is located on the rocker cover, near the crankcase breather.

Conditions for Running the Diagnostics

This diagnostic runs continuously when the engine is running at any rpm range.

Conditions for Setting the Fault Codes

The ECM detects that the crankcase pressure is greater than a calibrated value.

Action Taken When the Fault Code is Active

  • The ECM illuminates the RED ENGINE light when the crankcase pressure limit is exceeded.

Conditions for Clearing the Fault Code

The ECM will not turn off the red ENGINE light. The red light, derate and fault code will not clear even after key off. It will only be reset by the INSITE™ electronic service tool or recalibration.

Shop Talk

Possible causes of this fault code include:

  • Coolant in the oil
  • Crankcase pressure sensor damage
  • Plugged or restricted crankcase breather oil separator
  • Plugged or restricted crankcase breather oil drain tube
  • Plugged or restricted crankcase breather draft tube
  • Scuffed piston and/or cylinder liner
  • Damaged air compressor
  • Damaged turbocharger.

It is important to check for plugged or restricted hoses, tubes, check valves, and filters in extreme cold ambient temperatures.

If Fault Code 296lrv becomes active before the maintenance interval is reached or as the result of a scuffed piston or cylinder liner, reference the Engine Noise Excessive – Connecting Rod Excessive troubleshooting symptom tree in the Troubleshooting and Repair Manual ISC, ISCe, QSC8.3, ISL, ISLe3, ISLe4, and QSL9 Engines, Bulletin 4021418.

Refer to Troubleshooting Fault Code 296 (ISL Recreational Vehicles).

Last Modified:  20-Jul-2010