Fault Family System: Powertrain (P-Codes) 15 SAE Codes

EVAP Pressure Sensor Circuit

Diagnostic & Technical Explanation

Code P0450 (EVAP System Pressure Sensor/Switch A Circuit) sets when the ECM sees an open, shorted, out-of-range, or intermittent signal from the EVAP system's fuel tank pressure/vacuum sensor or switch used to run the leak-detection monitor. Causes are a corroded connector at the tank-top module, a failed sensor element, or chafed wiring between the sensor and the ECM.

These 15 diagnostic trouble codes share one detection mechanism and one repair path, which is why MechanicDB groups them into a single authored fault family rather than repeating the same explanation 15 times.

Codes in this family (15)

Code	Definition	Repair coverage
P0450	EVAP System Pressure Sensor/Switch A Circuit	4 ranked fixes
P0451	EVAP System Pressure Sensor/Switch A Circuit Range/Performance	4 ranked fixes
P0452	EVAP System Pressure Sensor/Switch A Circuit Low	4 ranked fixes
P0453	EVAP System Pressure Sensor/Switch A Circuit High	4 ranked fixes
P0454	EVAP System Pressure Sensor/Switch A Circuit Intermittent	4 ranked fixes
P24D5	EVAP System Pressure Sensor/Switch B Circuit	4 ranked fixes
P24D6	EVAP System Pressure Sensor/Switch B Circuit Range/Performance	4 ranked fixes
P24D7	EVAP System Pressure Sensor/Switch B Circuit Low	4 ranked fixes
P24D8	EVAP System Pressure Sensor/Switch B Circuit High	4 ranked fixes
P24D9	EVAP System Pressure Sensor/Switch B Circuit Intermittent	4 ranked fixes
P2B7A	EVAP System Pressure Sensor/Switch C Circuit	4 ranked fixes
P2B7B	EVAP System Pressure Sensor/Switch C Circuit Range/Performance	4 ranked fixes
P2B7C	EVAP System Pressure Sensor/Switch C Circuit Low	4 ranked fixes
P2B7D	EVAP System Pressure Sensor/Switch C Circuit High	4 ranked fixes
P2B7E	EVAP System Pressure Sensor/Switch C Circuit Intermittent	4 ranked fixes

What this page does not show

This page publishes the fault mechanism and the code index. The licensed dataset adds, for every one of the 15,886 codes, the full authored repair set (56,729 procedures in total) with the fields deliberately withheld here:

Procedures 2..n after the first-listed procedure
Aftermarket parts cost ranges in USD (est_parts_cost_min/max_usd)
Professional labor-hour estimates (est_labor_hours)
Step-by-step diagnostic and repair instructions
Replacement-part mappings and catalog lookups
6,637 manufacturer-specific OEM codes across 32 makes ($149 tier)

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