P CODE FAMILY

Powertrain code references — Page 74.

Engine, transmission and powertrain diagnostic references. Exact vehicle and module context still matters.

Generic OBD-II

P2423

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.

HC Adsorption Catalyst Efficiency Below Threshold Bank 1

HC Adsorption Catalyst Efficiency Below Threshold Bank 2

An EGR cooling-valve open-load report is an actuator-circuit finding

A low EGR cooling-valve circuit is distinct from an open-load fault

A high EGR cooling-valve circuit needs its own electrical evidence

exhaust protection checks both temperatures and temperature differences

Exhaust Gas Temperature Too High Bank 2

Ford exhaust-temperature sensor 3 model-plausibility fault

exhaust temperature sensor 3 fails to respond after a soak

exhaust temperature sensor 3 below its electrical range

exhaust temperature sensor 3 above its electrical range

exhaust temperature sensor 3 changes implausibly fast

DPF restriction and software must match the installed filter generation

AIR pressure can be stuck inside its electrical range

secondary-air pressure is compared before engine cranking

Low secondary-air pressure signal and why the voltage matters

High secondary-air pressure signal is not proof of high airflow

AIR System Air Flow/Pressure Sensor Circuit Intermittent/Erratic Bank 1

Bank 2 AIR pressure can fail while staying within range

Bank 2 AIR pressure rationality depends on pump state

Bank 2 AIR pressure low voltage relative to its reference

Bank 2 AIR pressure high voltage and the 94% boundary

AIR System Air Flow/Pressure Sensor Circuit Intermittent/Erratic Bank 2

Particulate Filter Restriction - Ash Accumulation Bank 2

Bank2 GPF restriction monitoring needs warm, sustained exhaust flow

Repeatedly short diesel particulate-filter regeneration intervals

Particulate Filter Regeneration Duration Bank 2

Particulate Filter Regeneration Incomplete Bank 2

Particulate Filter Restriction - Soot Accumulation Too High Bank 2

AIR valve stuck-open evidence comes from a closed-valve phase

AIR System Switching Valve Stuck Closed Bank 1

a bank 2 air-valve stuck-open judgment can use lambda correction

AIR valve stuck-closed code within a pressure-flow check

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