System: Powertrain (P-Code)
SAE Standard (Generic)
Family: Kickdown Switch Circuit
Code P278D: Kick Down Switch Circuit High
Diagnostic & Technical Explanation
Code P278D (Kick Down Switch Circuit High) sets when the TCM sees an open, shorted, implausible, or intermittent signal from the kick-down switch at the accelerator pedal's full-travel stop, used to force a downshift for maximum acceleration. Causes are a worn switch plunger no longer reaching its contact point, a corroded connector under the pedal assembly, or chafed wiring in the driver footwell harness.
First-listed procedure
Rank #1
Clean kick down 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: Kickdown Switch Circuit
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)