P278A
- Powertrain
- Manufacturer-specific
Diagnose soon
Usually safe to drive short distances, but the fault will not clear itself and can worsen or fail an emissions test.
Kick Down Switch Circuit
This code is in our catalogue but has not yet been through editorial review, so the guidance below is limited to what our structured data supports. We publish deeper diagnostic content only after a code has been reviewed — here is why.
The kick-down switch (under the accelerator pedal at full travel) circuit is faulty. The transmission cannot detect the driver's full-throttle downshift request.
A trouble code records what a control module measured. It does not identify which part failed. Test before replacing anything.
- Safe to drive
- Usually safe to drive short distances, but the fault will not clear itself and can worsen or fail an emissions test.
- Urgency
- Diagnose soon
- Will it pass emissions
- Not affected
- Check engine light
- Solid
| # | Cause | How often | Component |
|---|---|---|---|
| 1 | Switch contacts worn or corroded | Very common | — |
| 2 | Broken wire to switch | Common | — |
Ordering reflects how often each cause is responsible in general, not a probability for your vehicle. Confirm by testing.
- Kickdown Switch
- Accelerator Pedal
- Wiring Harness
- Definition
- Generic code set (SAE J2012 / ISO 15031-6) via the OBDexopen database, dedicated to the public domain under CC0-1.0.
- Diagnostic guidance
- Written and reviewed in-house. See our editorial policy.
- Review status
- Awaiting review
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