P2791Gate Select Direction Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2791 is set when the gate select direction signal sits below the lowest value the controller accepts. For a voltage-type sensor this usually points to a short to ground on the signal wire, a missing reference supply or a sensor pulling the line down internally; with switch-type inputs the contact may read as permanently closed to ground. The circuit fault P2790 and the high-side fault P2792 cover the other failure types of the same signal. No manufacturer documents P2791 publicly, so thresholds and debounce times are unknown; the check is one of the out-of-range tests CARB 13 CCR 1968.2 demands for transmission inputs. Measure supply and signal at the sensor connector before replacing the select actuator. The gearbox typically blocks lane changes and may freeze the current gear.
- What you may notice
- No change between shift lanes, limited gear choice
- Gearbox holds the current gear or selects neutral
- Transmission warning lamp
- Likely causes
- LikelySignal wire chafed and shorted to ground
- PossibleSensor reference voltage missing or shorted
- PossibleSelect direction sensor failed with low output
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €50 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.