System: Powertrain (P-Code)
SAE Standard (Generic)
Family: Alt Fuel Consumption Imbalance
Code P2BB1: Alternative Fuel Consumption Too High
Diagnostic & Technical Explanation
Code P2BB1 (Alternative Fuel Consumption Too High) 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.
First-listed procedure
Rank #1
Verify alternative fuel flow sensor calibration
Moderate DIY
This is the first procedure in the authored
consideration order, not a measured cause likelihood. Execute it only when its prerequisites
and diagnostic findings support it. Its cost and labor estimates (where known), the step-by-step procedure and the
remaining 2 procedure(s) are in the licensed dataset. Ordering context.
Full family: Alt Fuel Consumption Imbalance
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)