P2778 code meaning
Upshift Switch Circuit Intermittent/Erratic
What P2778 means
P2778 is meant for an upshift switch signal that jumps around or drops out briefly instead of staying in one state. No manufacturer documents P2778 publicly. GM's 2023/2024 twin-clutch TCM and Ford's TR9070 split the same paddle input into low, high, implausible and stuck faults (P2775–P2777, P0815) but list no intermittent check, so on those cars a flickering contact will rather end up as one of these. CARB expects inputs to be watched for circuit and rationality faults, which is the frame this code fits. Practical causes are a clock spring with a cracked track that opens at certain wheel angles, a loose crimp in the column connector, or a worn paddle contact. Symptoms come and go: occasional ignored upshifts or unwanted gear requests.
P2778 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 2.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2778
- Upshift requests occasionally ignored
- Occasional unwanted upshift requests
- Fault comes and goes, often depending on steering angle
Common causes of P2778
- Most likelyClock spring track cracked, opening at certain steering angles
- PossibleLoose terminal or poor crimp in the column or wheel connector
- PossibleWorn or bouncing contact in the paddle
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Upshift switchWiring harness
What each part of P2778 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. |
| 78 | The exact fault in that area. |
What to do next
- Note P2778 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 P2778
What does P2778 mean?
P2778 means "Upshift Switch Circuit Intermittent/Erratic". P2778 is meant for an upshift switch signal that jumps around or drops out briefly instead of staying in one state. It is a generic code, so it means the same on every make.
Is it safe to drive with P2778?
P2778 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will P2778 fail an emissions test?
P2778 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 P2778 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2.5 hours of work. This is a job for a workshop.
Will P2778 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.