Fault Family System: Powertrain (P-Codes) 10 SAE Codes

Alt Fuel Hydraulic Pressure Sensor

Diagnostic & Technical Explanation

Code P2A75 (Alternative Fuel Hydraulic Pump Pressure Sensor Circuit) covers the hydraulic pressure sensors that monitor either the fuel pump's hydraulic supply or the overall hydraulic actuation circuit on a bi-fuel injection pump system. The ECM flags an open, shorted, or out-of-range signal, or a reading that does not track commanded hydraulic pump output. Causes are a clogged sensor port restricting the pressure signal, a failed sensor element, or corroded wiring at the sensor connector.

These 10 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 10 times.

Codes in this family (10)

Code	Definition	Repair coverage
P2A75	Alternative Fuel Hydraulic Pump Pressure Sensor Circuit	4 ranked fixes
P2A76	Alternative Fuel Hydraulic Pump Pressure Sensor Range/Performance	4 ranked fixes
P2A77	Alternative Fuel Hydraulic Pump Pressure Sensor Circuit Low	4 ranked fixes
P2A78	Alternative Fuel Hydraulic Pump Pressure Sensor Circuit High	4 ranked fixes
P2A79	Alternative Fuel Hydraulic Pump Pressure Sensor Circuit Intermittent/Erratic	4 ranked fixes
P2A7A	Alternative Fuel Hydraulic Pressure Sensor Circuit	4 ranked fixes
P2A7B	Alternative Fuel Hydraulic Pressure Sensor Range/Performance	4 ranked fixes
P2A7C	Alternative Fuel Hydraulic Pressure Sensor Circuit Low	4 ranked fixes
P2A7D	Alternative Fuel Hydraulic Pressure Sensor Circuit High	4 ranked fixes
P2A7E	Alternative Fuel Hydraulic Pressure Sensor Circuit Intermitttent/Erratic	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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