Fault Family
System: Powertrain (P-Codes)
2 SAE Codes
Alt Fuel Consumption Imbalance
Diagnostic & Technical Explanation
Code P2BB0 (Alternative Fuel Consumption Too Low) sets when the ECM compares commanded alternative-fuel injector duty cycle against actual fuel consumed (calculated from tank level drop or a flow meter) and finds the two disagree by more than the allowed tolerance. Consumption reading too low points to a restricted supply line or a failing flow sensor; too high points to a leaking injector, a stuck-open valve, or a miscalibrated flow sensor.
These 2 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 2 times.
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)