Fault Family System: Powertrain (P-Codes) 5 SAE Codes

Alt Fuel Hydraulic Valve Control

Diagnostic & Technical Explanation

Code P2A70 (Alternative Fuel Hydraulic Fuel Pump Select Valve Control Circuit) applies to bi-fuel systems that use a hydraulically actuated fuel pump select valve to route liquid alternative fuel to the injection pump. The ECM detects an open circuit, an out-of-range voltage, or a valve that fails to reach its commanded position within the expected hydraulic response window. Contamination in the hydraulic fluid fouling the valve spool, a failed solenoid coil, or damaged control wiring are the usual causes.

These 5 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 5 times.

Codes in this family (5)

Code	Definition	Repair coverage
P2A70	Alternative Fuel Hydraulic Fuel Pump Select Valve Control Circuit	4 ranked fixes
P2A71	Alternative Fuel Hydraulic Fuel Pump Select Valve Control Range/Performance	4 ranked fixes
P2A72	Alternative Fuel Hydraulic Fuel Pump Select Valve Control Circuit Low	4 ranked fixes
P2A73	Alternative Fuel Hydraulic Fuel Pump Select Valve Control Circuit High	4 ranked fixes
P2A74	Alternative Fuel Hydraulic Fuel Pump Select Valve Control Circuit Intermittent/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)

Need All 15,886 Codes as Data?

Pipe-delimited CSV, Apache Parquet and a relational SQLite database, with commercial application rights and instant download. Built for scan tools, shop software and research - not assembled one web page at a time.

License OEM Complete · $149 Standard (SAE only) · $49

$49 Standard: 9,249 SAE codes · $149 OEM Complete: all 15,886 codes, including 6,637 OEM codes across 32 makes · $149 Heavy Duty: 4,212 fault pairs (J1939) · one-time · compare tiers