OBD-II code · Powertrain (generic, extended)
P2778 Upshift Switch Circuit Intermittent/Erratic
The upshift switch signal jumps or drops out intermittently. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
Is it safe to drive with P2778?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySteering wheel connector loose
- PossibleWear in steering wheel clock spring contacts
- Less likelyConnector with intermittent contact under vibration
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.8–3 h
- Emissions test
- Usually unaffected
- Parts involved
- Upshift Switch, Wiring Harness
Related codes
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.