P278E code meaning
Kick Down Switch Circuit Intermittent/Erratic
What P278E means
P278E stands for a kickdown switch signal that drops out or toggles irregularly. No manufacturer documents P278E publicly; the monitoring idea follows CARB's call for circuit checks on inputs, and Eaton's Endurant HD diagnostics show the networked equivalent, where a kickdown message that is invalid or absent for 5 s is logged as fault 167. Intermittent faults at the pedal usually come from a contact that bounces as the detent wears, a connector that loosens with pedal vibration, or a harness that flexes with every pedal stroke until a strand breaks. Because the fault is not permanent, a scan with the car at rest often finds nothing. The driver feels kickdown working on one occasion and not on the next.
P278E at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyEasy, DIY possible
- Typical labor0.3 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P278E
- Kickdown works only sometimes
- Fault not reproducible when stationary
Common causes of P278E
- Most likelyBouncing switch contact due to worn detent
- PossiblePedal connector loosened by vibration
- PossibleWire strands breaking where the harness flexes with the pedal
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Kickdown switchWiring harness
What each part of P278E means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 7 | Area: transmission. |
| 8E | The exact fault in that area. |
What to do next
- Note P278E and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P278E
What does P278E mean?
P278E means "Kick Down Switch Circuit Intermittent/Erratic". P278E stands for a kickdown switch signal that drops out or toggles irregularly. It is a generic code, so it means the same on every make.
Is it safe to drive with P278E?
P278E does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will P278E fail an emissions test?
P278E is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is P278E to fix?
Difficulty: easy. A typical repair takes 0.3 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P278E clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.