Cummins ISB4.5 CM2150 Fault Code: 499 PID: 98 SPN: 98 FMI: 4 Engine Oil Level Sensor Circuit – Voltage Below Normal or Shorted to Low Source.

Circuit Description
The oil level sensor will monitor the oil fluid level in the oil pan at key-on. The oil level sensor will not monitor the oil level after the engine is started or when the engine speed is greater than 0 rpm. During the engine key-on, if the oil level sensor detects a critical low oil level, the amber CHECK ENGINE light will blink for 30 seconds and a fault code will be logged. If an operator observes a blinking amber CHECK ENGINE light at key-on, the operator must check the engine oil level with the manual dipstick.

The oil level sensor provides the electronic control module (ECM) with a pulse width modulated (PWM) signal. Within this signal, the oil level sensor transmits the engine oil level reading, oil temperature, and fault code information from the oil level sensor.

Component Location
The oil level sensor is located on the left side of the engine on the front oil dipstick port.

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

Conditions for Setting the Fault Codes
The oil level sensor has detected an internal short or open circuit.

Action Taken When the Fault Code is Active
-The ECM illuminates the amber CHECK ENGINE light immediately when the diagnostic runs and fails.
-The oil level sensor operation will be disabled.

Conditions for Clearing the Fault Code
-The ECM will turn off the amber CHECK ENGINE light and enable oil level sensor operation immediately after a valid PWM signal is received from the oil level sensor.
-The inactive fault code can then be cleared with INSITE™ electronic service tool.

Possible Causes
-Open or short circuit internally to the oil level sensor
-A malfunctioned oil level sensor