Fault Family
System: Powertrain (P-Codes)
2 SAE Codes
Fuel Trim General
Diagnostic & Technical Explanation
Code P0170 (Fuel Trim Bank 1) sets when overall short- or long-term fuel trim for a bank moves outside its normal operating window without a specific lean or rich bias being isolated. Causes span vacuum leaks, a fuel delivery imbalance, or a fuel/air metering sensor reading incorrectly for that bank.
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)