P2780Downshift Switch Circuit Low
- Generic OBD-II code · Powertrain
- How the car detects it
- P2780 tells you the downshift switch voltage has fallen under its lower limit. GM's twin-clutch TCM (tables 23OBDG07 and 24OBDG07) checks the TAPDN input against 2.519 V; if the signal stays under that mark for 150 ms while the supply is inside 8.75–18 V and the starter is not engaged, P2780 is logged as Type C, no MIL. In Ford's TR9070 listing from July 2024, P2780 is the out-of-window-low entry for the downshift paddle. A minus-paddle signal pulled toward ground usually comes from a wire rubbed through near the steering column, a pinched harness behind the wheel trim or an internal short in the switch. P2781 is the high-side failure, P2779 the implausible value within range. Manual downshifts are lost; automatic operation carries on.
- What you may notice
- Downshift paddle has no effect
- Manual mode not available, normally no check engine light
- Likely causes
- LikelySignal wire rubbed through or pinched to ground
- PossibleMinus paddle shorted internally
- Repair
- Medium · Usually a job for a workshop.Typical cost: €60 – €500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.