DTC B250B Dodge

Description

The Fuel Level Sensor information is a bussed message from the Body Control Module (BCM) to the Powertrain Control Module (PCM). The intent of the Fuel Level Rationality is to check for a stuck fuel level reading. This is done to keep high or low fuel levels that are stuck from disabling OBD monitors. If a fault is set, the fuel level will default to a value that will allow the OBD diagnostics to run. Since the amount of fuel consumed from trip to trip varies based on customer drive cycles, this diagnostic can accumulate fuel consumption over multiple drive cycles. The diagnostic will run until enough fuel has been consumed to make a decision. The PCM compares the difference between the fuel level value at the start of the diagnostic and the fuel level value after a calibrated amount of fuel consumption should have occurred. If the difference is less than a calibrated threshold, the test fails. Once a decision is made, a new diagnostic test will start.