MANUFACTURER REFERENCE

Generic OBD-II code references — Page 20.

Read the source definition and confirm the exact vehicle, reporting module and diagnostic procedure.

Generic OBD-II

P04D5

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.

Exhaust Brake Input Circuit Low

Exhaust Brake Input Circuit High

Exhaust Brake Input Circuit Intermittent/Erratic

Excessive Time To Enter Closed Loop EGR Control

Low EGR flow reaches the closed-loop control limit

Excessive EGR flow is detected as a control-ratio error

Crankcase ventilation judged by pressure offset and pulsation

Fuel Fill Door Position Sensor/Switch Circuit Range/Performance

cold-start EGR insufficient flow uses an operating-point-dependent limit

cold-start EGR excessive flow compares modeled and measured air mass

bank-1 purge-valve response during intrusive testing

EVAP System Purge Control Valve A Stuck Closed

Crankcase Ventilation Hose Connection Sensor Circuit

PCV hose pressure signal low from an open or ground short

PCV hose pressure output above its electrical ceiling

Crankcase Ventilation Hose Connection Sensor Circuit Intermittent/Erratic

EGR Temperature Sensor D Circuit

EGR Temperature Sensor D Circuit Range/Performance

EGR Temperature Sensor D Circuit Low

EGR Temperature Sensor D Circuit High

EGR Temperature Sensor D Circuit Intermittent/Erratic

EVAP System Small Leak Detected - Fuel Tank Side

EVAP System Small Leak Detected - Fresh Air Side

EVAP System Large Leak Detected - Fuel Tank Side

EVAP System Large Leak Detected - Fresh Air Side

Wrangler tank-side leak from a trapped cap tether

EVAP System Very Small Leak Detected - Fresh Air Side

High-load EVAP purge behavior is tested under boost

EVAP System Purge Line Performance

Catalyst Heater Supply Voltage Bank 1

Catalyst Heater Supply Voltage Bank 2

Catalyst Heater Circuit Low Bank 1

Catalyst Heater Circuit Low Bank 2

Catalyst Heater Circuit High Bank 1

Catalyst Heater Circuit High Bank 2

Catalyst Heater Circuit Intermittent Bank 1

Catalyst Heater Circuit Intermittent Bank 2

high-pressure EGR drive electronics overtemperature

PCV pressure should approach atmosphere after engine rotation stops

Chrysler 300 crankcase-ventilation performance software case

EGR Actuator A Control Processor Performance

Catalyst Heater Circuit Performance Bank 1

Catalyst Heater Circuit Performance Bank 2

A diesel vehicle-speed code can describe missing CAN information

An implausibly high vehicle-speed report in a manual-transmission example

Two vehicle-speed paths disagree in the Duramax monitor

Abrupt transmission output-speed changes need context

Brake-switch correlation is accumulated across braking events

Maxima idle-air diagnosis includes learning and two fault branches

Idle speed stays below the controller's target

Idle speed remains higher than a stable commanded target

Idle Air Control System Circuit Low

Idle Air Control System Circuit High

cold-start idle error during catalyst heating

Cold-start timing performance is compared with catalyst-heating intent

Cold-start coolant plausibility uses prior heat history

Incomplete combustion during the cold-start dual-pulse strategy

Cold-start exhaust warming is evaluated through a temperature model

Brake Assist Vacuum Too Low

Altima reports closed throttle while the valve is open

Ford idle-air control electrical fault versus idle-speed error

Diesel Cherokee starter-request fault from transmission-harness rubbing

Pacifica hybrid no-start and paired control-module software

preserve the Jeep diesel temperature-signal subtype

Battery Temperature Sensor Circuit

Battery Temperature Sensor Circuit Low

Battery Temperature Sensor Circuit High

Idle Air Control Circuit Intermittent

Idle Air Control System Performance

A digital crankcase-pressure sensor fault is not a PCV hose diagnosis

Crankcase-pressure rationality can fail without an electrical extreme

Low crankcase-pressure sensor voltage is an analog circuit result

High crankcase-pressure sensor voltage does not prove high physical pressure

Crankcase Pressure Sensor A Circuit Intermittent/Erratic

PCV Filter Restriction

Distinguish a digital oil-pressure fault from an analog voltage limit

Oil-pressure plausibility depends on pump stage and operating state

Oil-pressure sensor output below its reference-relative range

Oil-pressure sensor high output needs electrical validation

Low oil-pressure detection uses a mapped limit and debounce