System: Powertrain (P-Code)
SAE Standard (Generic)
Family: Fuel Mode Select Switch
Code P25A8: Fuel Mode Select Switch Circuit Intermittent/Erratic
Diagnostic & Technical Explanation
Code P25A8 (Fuel Mode Select Switch Circuit Intermittent/Erratic) sets when the ECM sees an open, shorted, implausible, or intermittent signal from the driver's fuel-mode select switch used on bi-fuel vehicles to choose between gasoline and the alternative fuel (CNG/LPG/E85). Causes are worn switch contacts, a corroded connector in the dash harness, or chafed wiring between the switch and the fuel-selection module.
First-listed procedure
Rank #1
Clean fuel mode switch contacts
Easy 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: Fuel Mode Select Switch
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)