B14FB Code: Meaning, Causes, and Symptoms | OBD2 Codes
B14FB – Low Side Driver 4
B14FB Possible Symptoms
Engine Light ON (or Service Engine Soon Warning Light)
B14FB Possible Causes
Faulty Upfitter Interface Module,Upfitter Interface Module harness is open or shorted,Upfitter Interface Module circuit poor electrical connection
The Upfitter Interface Module utilizes a Field Effect Transistor (FET) protective circuit strategy to protect the low and high side driver output circuits. Output loads (current levels) are monitored for excessive current (which is typically caused by a short circuit to ground) and are shut down (turns off the voltage or ground provided by the module) when a fault is detected. A short to battery voltage occurring on either a low or high side driver output circuit may also result in a temporarily loss of operation in the output circuit (no voltage or ground will be applied to the output circuit) to protect the module against a potential over temperature condition. A Field Effect Transistor (FET) is a type of transistor that the module uses to control and monitor current flow on module output circuits. The Field Effect Transistor (FET) protection strategy prevents damage from occurring to the module. Whenever a FET is turned off because of a fault condition a Diagnostic Trouble Code (DTC) is set in the module which corresponds to the specific fault observed. The module resets the Field Effect Transistor (FET) protection and allows the circuit to function when the fault is corrected or the ignition is cycled off and then back on. The ignition should always be cycled from off to on after a fault is corrected to ensure that FET protection is reset.