OBD-II code family
EVAP Pressure Input Faults (5 codes)
5 related fault descriptions. Use each full code and the exact vehicle service information to identify its circuit, monitored condition, and required tests.
Codes in this family
This is the complete published member list for this guide. Each code retains its own page; shared diagnostic context does not mean that every member has the same test or repair.
- P0450Evaporative Emission System Pressure Sensor/Switch
- P0451Evaporative Emission System Pressure Sensor/Switch Range/Performance
- P0452Evaporative Emission System Pressure Sensor/Switch Low
- P0453Evaporative Emission System Pressure Sensor/Switch High
- P0454Evaporative Emission System Pressure Sensor/Switch Intermittent
What these codes mean
P0450 identifies EVAP pressure sensor/switch context; P0451 distinguishes range/performance, P0452 low input, P0453 high input and P0454 intermittent input. These pressure-information faults do not by themselves locate a leak or prove that a pressure sensor needs replacement.
A measured electrical signal, real tank pressure and a scan tool’s converted or substitute pressure value are different observations. Low/high cannot be translated into one universal pressure/vacuum, open/short or safe/unsafe conclusion. Identify the sensor or switch design, terminal functions, reference conditions and full fault subtype first.
Ford’s covered summary distinguishes low/high, noisy-input and offset checks through complete codes and calibration. Range/performance does not certify healthy wiring, while a normal idle reading does not rule out an intermittent condition evaluated elsewhere. Another model’s atmospheric or unplugged voltage is not a generic specification.
On the vehicles covered by Infiniti ITB22-042, companion P0451/P0452/P0454 with P0448 changes the diagnostic branch toward the pressure-sensor path. The combination does not make an isolated pressure code an automatic sensor-replacement instruction. Preserve the complete scan and event conditions before clearing faults.
Inspect accessible cooled wiring using the correct diagram, then have the specified signal, supply, return and pressure/reference checks performed. Do not bridge terminals or open fuel/vapor connections simply to force a normal reading. Required pressure release, filler access and test equipment come from the actual procedure. Repair the demonstrated circuit, component or pressure-control fault and verify input validity and monitor evaluation before pricing unrelated EVAP work.
Identify the circuit on your vehicle
Match the full DTC, reporting module, and any failure-type suffix to the service information for your exact year, make, model, engine, and equipment. An identifier alone does not establish installed hardware count, location, connector pinout, or a universal measurement.
Where the manufacturer publishes its own meaning for this code, that is the one to work from — it describes the actual component on your vehicle, which the generic definition cannot. Keep the generic description for what it is good for: it tells you which subject area the standard assigned the code to, which is useful context when the two appear to disagree. If they do disagree, follow the manufacturer.