THE CODE DIRECTORY

Diagnostic code references — Page 81.

Browse canonical reference entries. Each definition keeps its own source and vehicle-applicability limits.

Generic OBD-II

P2444

These are code references, not a list of confirmed faults on every vehicle. Read the source and applicability notes, then match the exact vehicle, year, engine and scan report.

AIR pump stuck-on wording can describe a control-circuit fault

AIR pump stuck-off wording and the ground-side electrical check

AIR System Pump Stuck On Bank 2

AIR System Pump Stuck Off Bank 2

AIR System High Air Flow Bank 1

AIR System High Air Flow Bank 2

particulate-filter differential pressure is unexpectedly low

filter pressure comparison suggests a downstream sensing problem

Regeneration temperature falls short of a changing target

Exhaust Temperature Too High For Particulate Filter Regeneration Bank 1

Exhaust Temperature Too Low For Particulate Filter Regeneration Bank 2

Exhaust Temperature Too High For Particulate Filter Regeneration Bank 2

EVAP switching valve produces too little pressure change

Ford hybrid EVAP test can mislead unless the fuel-door sequence is followed

particulate-filter pressure sensor offset is implausible

filter differential-pressure signal is stuck during a transient

filter differential-pressure raw signal below its electrical floor

filter pressure-sensor signal above its electrical ceiling

filter differential-pressure signal jumps too rapidly

EGR cooler undercooling is evaluated against coolant temperature

extended regeneration time is different from a measured soot limit

DPF regeneration starts too often relative to modeled soot

The cooler-bypass open check requires an off driver but a non-closed request

EGR bypass performance is checked through temperature response

EGR cooler bypass circuit low and H-bridge overcurrent

EGR cooler bypass circuit high under motor command

Digital pressure sensor B circuit status differs from an analog voltage fault

Pressure-sensor B performance is assessed after electrical checks

Low pressure-sensor B voltage does not directly prove low filter pressure

High pressure-sensor B voltage is not a filter-restriction measurement

Intermittent pressure-sensor B faults need a time record, not one good reading

DPF soot estimate reaches the service-regeneration range

Particulate Filter Differential Pressure Too Low Bank 2

Particulate Filter Differential Pressure Too High Bank 2

Exhaust Gas Temperature Sensor Circuit Bank 2 Sensor 3

coolant-loss diagnosis in Ford’s 2.0L EcoBoost EGR-cooler case

Exhaust Gas Temperature Sensor Circuit Low Bank 2 Sensor 3

Exhaust Gas Temperature Sensor Circuit High Bank 2 Sensor 3

Exhaust Gas Temperature Sensor Circuit Intermittent/Erratic Bank 2 Sensor 3

Vehicle Conditions Incorrect for Particulate Filter Regeneration

DPF restriction reaches the forced-power-limitation threshold

Ford DPF pressure sensors disagree under exhaust flow

identify exhaust-temperature sensor 4 before trusting its display label

Exhaust sensor 4 fails to warm plausibly after a soak

Exhaust temperature sensor 4 below its valid input range

High-range exhaust temperature sensor 4 input

EGT sensor 4 intermittent signal and rapid-change monitoring

Exhaust Gas Temperature Sensor Circuit Bank 2 Sensor 4

Exhaust Gas Temperature Sensor Circuit Range/Performance Bank 2 Sensor 4

Exhaust Gas Temperature Sensor Circuit Low Bank 2 Sensor 4

Exhaust Gas Temperature Sensor Circuit High Bank 2 Sensor 4

Exhaust Gas Temperature Sensor Circuit Intermittent/Erratic Bank 2 Sensor 4

Ford exhaust-temperature sensor 1 exceeds engineering range

Ford exhaust-temperature sensor 2 high engineering-range fault

Ford exhaust-temperature sensor 3 exceeds its upper range

Ford exhaust-temperature sensor 4 upper-range fault

Exhaust Gas Temperature Out of Range Bank 2 Sensor 1

Exhaust Gas Temperature Out of Range Bank 2 Sensor 2

Exhaust Gas Temperature Out of Range Bank 2 Sensor 3

Exhaust Gas Temperature Out of Range Bank 2 Sensor 4

Exhaust Gas Temperature Sensor Circuit/Open Bank 1 Sensor 5

EGT sensor 5 circuit low across analog and digital systems

EGT sensor 5 circuit high and architecture-specific thresholds

EGT sensor 5 response plausibility after an engine-off soak

EGT sensor 5 intermittent signal and temperature-step evidence

Exhaust Gas Temperature Sensor Circuit/Open Bank 2 Sensor 5

Exhaust Gas Temperature Sensor Circuit Low Bank 2 Sensor 5

Exhaust Gas Temperature Sensor Circuit High Bank 2 Sensor 5

Exhaust Gas Temperature Sensor Circuit Range/Performance Bank 2 Sensor 5

Exhaust Gas Temperature Sensor Circuit Intermittent/Erratic Bank 2 Sensor 5

Reductant heater A supply low in the GM tank-heater monitor

Reductant heater A supply high relative to the powertrain relay

Reductant heater B supply low in the GM line-heater monitor

A DEF heater sense-high result is a voltage comparison

EGR Cooler Bypass Control Circuit/Open Bank 2

EGR Cooler Bypass Control Circuit Range/Performance Bank 2

EGR Cooler Bypass Control Circuit Low Bank 2

EGR Cooler Bypass Control Circuit High Bank 2

EGR Cooler Bypass Position Sensor Circuit Bank 1

EGR bypass tracking depends on completed offset learning